# Linear congruential generator

The linear congruential generator is a very simple example of a random number generator.

Linear congruential generator
You are encouraged to solve this task according to the task description, using any language you may know.

All linear congruential generators use this formula:

• ${\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}$

Where:

• ${\displaystyle r_{0}}$ is a seed.
• ${\displaystyle r_{1}}$, ${\displaystyle r_{2}}$, ${\displaystyle r_{3}}$, ..., are the random numbers.
• ${\displaystyle a}$, ${\displaystyle c}$, ${\displaystyle m}$ are constants.

If one chooses the values of ${\displaystyle a}$, ${\displaystyle c}$ and ${\displaystyle m}$ with care, then the generator produces a uniform distribution of integers from ${\displaystyle 0}$ to ${\displaystyle m-1}$.

LCG numbers have poor quality. ${\displaystyle r_{n}}$ and ${\displaystyle r_{n+1}}$ are not independent, as true random numbers would be. Anyone who knows ${\displaystyle r_{n}}$ can predict ${\displaystyle r_{n+1}}$, therefore LCG is not cryptographically secure. The LCG is still good enough for simple tasks like Miller-Rabin primality test, or FreeCell deals. Among the benefits of the LCG, one can easily reproduce a sequence of numbers, from the same ${\displaystyle r_{0}}$. One can also reproduce such sequence with a different programming language, because the formula is so simple.

The task is to replicate two historic random number generators. One is the rand() function from BSD libc, and the other is the rand() function from the Microsoft C Runtime (MSCVRT.DLL). Each replica must yield the same sequence of integers as the original generator, when starting from the same seed.

In these formulas, the seed becomes ${\displaystyle state_{0}}$. The random sequence is ${\displaystyle rand_{1}}$, ${\displaystyle rand_{2}}$ and so on.

BSD formula
• ${\displaystyle state_{n+1}=1103515245\times state_{n}+12345{\pmod {2^{31}}}}$
• ${\displaystyle rand_{n}=state_{n}}$
• ${\displaystyle rand_{n}}$ is in range 0 to 2147483647.

Microsoft formula
• ${\displaystyle state_{n+1}=214013\times state_{n}+2531011{\pmod {2^{31}}}}$
• ${\displaystyle rand_{n}=state_{n}\div 2^{16}}$
• ${\displaystyle rand_{n}}$ is in range 0 to 32767.

The BSD formula was so awful that FreeBSD switched to a different formula.

More info is at Random number generator (included)#C.

## 11l

T LinearCongruentialGenerator
seed = 0
Int a, c, m

F (a, c, m)
.a = a
.c = c
.m = m

F ()()
.seed = (.a * .seed + .c) [&] .m
R .seed

V bsd_rnd = LinearCongruentialGenerator(1103515245, 12345, 7FFF'FFFF)
V ms_rnd  = LinearCongruentialGenerator(214013, 2531011, 7FFF'FFFF)

print(‘BSD RAND:’)
L 5
print(bsd_rnd())
print()
print(‘MS RAND:’)
L 5
print(ms_rnd() >> 16)
Output:
BSD RAND:
12345
1406932606
654583775
1449466924
229283573

MS RAND:
38
7719
21238
2437
8855


## 360 Assembly

*        Linear congruential generator   07/03/2017
LINCONG  CSECT
USING  LINCONG,R12
LR     R12,R15            set base register
BEGIN    SR     R5,R5              bsdseed=0
SR     R7,R7              msseed=0
LA     R8,1               i=1
L      R9,=F'10'          number of loop
LOOP     M      R4,=F'1103515245'  bsdseed*=1103515245
A      R5,=F'12345'       bsdseed+=12345
LR     R3,R5              bsdrand=bsdseed
LTR    R5,R5              if bsdseed<0
BP     CONT               then
L      R3,COMP2             -2**31
SR     R3,R5                -bsdseed
LPR    R3,R3                bsdrand=abs(-2**31-bsdseed)
CONT     M      R6,=F'214013'      msseed*=214013
A      R7,=F'2531011'     msseed+=2531011
XR     R6,R6
D      R6,TWO16           /2**16
XDECO  R8,XDEC            i
MVC    PG(4),XDEC+8
XDECO  R3,XDEC            bsdrand
MVC    PG+4(12),XDEC
XDECO  R7,XDEC            msseed
MVC    PG+16(7),XDEC+5
XPRNT  PG,L'PG            print buffer
LA     R8,1(R8)           i=i+1
BCT    R9,LOOP            loop
RETURN   XR     R15,R15            set return code
DS     0F                 alignment
TWO16    DC     XL4'00010000'      2**16
COMP2    DC     XL4'80000000'      -2**31
PG       DC     CL80' '
XDEC     DS     CL12
YREGS
END    LINCONG
Output:
   1       12345     38
2  1406932606    162
3   654583775    567
4  1449466924   1890
5   229283573   6210
6  1109335178  20317
7  1051550459    849
8  1293799192   2811
9   794471793   9218
10   551188310  30140


We first specify a generic package LCG:

generic
type Base_Type is mod <>;
Output_Divisor: Base_Type := 1;
package LCG is

procedure Initialize(Seed: Base_Type);
function Random return Base_Type;
-- changes the state and outputs the result

end LCG;


Then we provide a generic implementation:

package body LCG is

State: Base_Type := Base_Type'First;

procedure Initialize(Seed: Base_Type) is
begin
State := Seed;
end Initialize;

function Random return Base_Type is
begin
State := State * Multiplyer + Adder;
return State / Output_Divisor;
end Random;

end LCG;


Next, we define the MS- and BSD-instantiations of the generic package:

with Ada.Text_IO, LCG;

procedure Run_LCGs is

type M31 is mod 2**31;

package BSD_Rand is new LCG(Base_Type => M31, Multiplyer => 1103515245,

package MS_Rand  is new LCG(Base_Type => M31, Multiplyer => 214013,
Adder => 2531011, Output_Divisor => 2**16);

begin
for I in 1 .. 10 loop
end loop;
for I in 1 .. 10 loop
end loop;
end Run_LCGs;


Finally, we run the program, which generates the following output (note that the first ten lines are from the BSD generator, the next ten from the MS generator):

 12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## ALGOL 68

BEGIN
COMMENT
Algol 68 Genie checks for integer overflow whereas the reference
language leaves the result undefined so for portability we need to
see how wide a variable must be to hold the maximum possible value
before range reduction. This occurs in the BSD RNG when
rseed=2147483647 and is therefore 2147483647 * 1103515245 + 12345 =
2369780942852710860, which itself is 19 decimal digits.  Use
evironmental queries to determine the width needed.
COMMENT
MODE RANDINT = UNION (INT, LONG INT, LONG LONG INT);
RANDINT rseed := (int width > 18 | 0 |:
long int width > 18 |
LONG 0 | LONG LONG 0);
PROC srand = (INT x) VOID :
(rseed | (INT): rseed := x,
(LONG INT): rseed := LENG x | rseed := LENG LENG x);
PROC bsd rand = INT :
BEGIN
CASE rseed IN
(INT ri):
BEGIN
INT a = 1103515245, c = 12345, m1 = 2^16, m2 = 2^15;
COMMENT
That curious declaration is because 2^31 might overflow during
compilation but the MODE declaration for RANDINT guarantees that it
will not overflow at run-time.  We assume that an INT is at least
32 bits wide, otherwise a similar workaround would be needed for
the declaration of a.
COMMENT
INT result = (ri * a + c) MOD (m1 * m2); rseed := result;
result
END,
(LONG INT rli):
BEGIN
LONG INT a = LONG 1103515245, c = LONG 12345, m = LONG 2^31;
LONG INT result = (rli * a + c) MOD m; rseed := result;
SHORTEN result
END,
(LONG LONG INT rlli) :
BEGIN
LONG LONG INT a = LONG LONG 1103515245,
c = LONG LONG 12345, m = LONG LONG 2^31;
LONG LONG INT result = (rlli * a + c) MOD  m; rseed := result;
SHORTEN SHORTEN result
END
ESAC
END;
PROC ms rand = INT :
BEGIN
CASE rseed IN
(INT ri):
BEGIN
INT a = 214013, c = 2531011, m1 = 2^15, m2 = 2^16;
INT result = (ri * a + c) MOD (m1 * m2); rseed := result;
result % m2
END,
(LONG INT rli):
BEGIN
LONG INT a = LONG 214013, c = LONG 2531011, m = LONG 2^31, m2 = LONG 2^16;
LONG INT result = (rli * a + c) MOD m; rseed := result;
SHORTEN (result % m2)
END,
(LONG LONG INT rlli) :
BEGIN
LONG LONG INT a = LONG LONG 214013,
c = LONG LONG 2531011, m = LONG LONG 2^31, m2 = LONG LONG 2^16;
LONG LONG INT result = (rlli * a + c) MOD m; rseed := result;
SHORTEN SHORTEN (result % m2)
END
ESAC
END;
srand (0);
TO 10 DO printf (($g(0)l$, bsd rand)) OD;
print (newline);
srand (0);
TO 10 DO printf (($g(0)l$, ms rand)) OD;
srand (0)
END
Output:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## AutoHotkey

a := 0, b:= [0]
Loop, 10
BSD .= "t" (a :=  BSD(a)) "n"
,	b := MS(b[1])
,	MS .= "t" (b[2]) "n"

MsgBox, % "BSD:n" BSD "nMS:n" MS

BSD(Seed) {
return, Mod(1103515245 * Seed + 12345, 2147483648)
}

MS(Seed) {
Seed := Mod(214013 * Seed + 2531011, 2147483648)
return, [Seed, Seed // 65536]
}


Output:

BSD:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

MS:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## Batch File

@echo off & setlocal enabledelayedexpansion

echo BSD Rand
set /a a=0,cnt=1
:b
set /a "a=1103515245 *a+12345,a&=0x7fffffff, cnt+=1"
call:prettyprint !cnt! !a!
if !cnt! leq 10 goto :b

echo.
echo Microsoft Rand
set /a a=0,cnt=1
:c
set /a "a=214013 *a+2531011,a&=0x7fffffff, b=a>>16,cnt+=1"
call:prettyprint !cnt! !b!
if !cnt! lss 10 goto :c
pause
goto:eof

:prettyprint
set p1= %1
set p2=        %2
echo %p1:~-2%  %p2:~-10%
goto:eof

Output:

BSD Rand
2       12345
3  1406932606
4   654583775
5  1449466924
6   229283573
7  1109335178
8  1051550459
9  1293799192
10   794471793
11   551188310

Microsoft Rand
2          38
3        7719
4       21238
5        2437
6        8855
7       11797
8        8365
9       32285
10       10450


## BBC BASIC

      @% = &D0D
PRINT "MS generator:"
dummy% = FNrandMS(0)
FOR i% = 1 TO 10
PRINT FNrandMS(-1)
NEXT
PRINT '"BSD generator:"
dummy% = FNrandBSD(0)
FOR i% = 1 TO 10
PRINT FNrandBSD(-1)
NEXT
END

DEF FNrandMS(seed%)
PRIVATE state%
IF seed% >= 0 THEN
state% = seed%
ELSE
state% = FNmuladd(state%, 214013, 2531011)
ENDIF
= state% >> 16

DEF FNrandBSD(seed%)
PRIVATE state%
IF seed% >= 0 THEN
state% = seed%
ELSE
state% = FNmuladd(state%, 1103515245, 12345)
ENDIF
= state%

DEF FNmuladd(A%,B%,C%) : PRIVATE M% : LOCAL P% : IF M% = 0 DIM P% 8
IF P% THEN [OPT 0 : .M% mul ebx : add eax,ecx : btr eax,31 : ret :]
= USR M%


Output:

MS generator:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

BSD generator:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310


## bc

Translation of: dc
Works with: GNU bc
Works with: OpenBSD bc

As with dc, bc has no bitwise operators.

/* BSD rand */

define rand() {
randseed = (randseed * 1103515245 + 12345) % 2147483648
return randseed
}

randseed = 1
rand(); rand(); rand(); print "\n"

/* Microsoft rand */

define rand() {
randseed = (randseed * 214013 + 2531011) % 2147483648
return randseed / 65536
}

randseed = 1
rand(); rand(); rand(); print "\n"


## Befunge

This required a bit of trickery to handle signed overflow and negative division in a portable way. It still won't work on all implementations, though. In particular Javascript-based interpreters can't handle the BSD formula because of the way Javascript numbers lose their least significant digits when they become too large.

>025*>\::0\288*::*:****+.55+,"iQ"5982156*:v
v $$_^#!\-1:\%***:*::*882 ++*"yf"3***+***+*< >025*>\:488**:*/:0\6"~7"+:*+01-2/-*+."O?+"55v @$$_^#!\-1:\%***:*::*882 ++***" ''4C"*+2**,+<

Output:
0
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310
0
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## Bracmat

( 2^31:?RANDMAX
& 2^-16:?rshift
& (randBSD=mod$(!seed*1103515245+12345.!RANDMAX):?seed) & ( randMS = div$ ((mod$(!seed*214013+2531011.!RANDMAX):?seed)*!rshift.1) ) & out$\nBSD
& 0:?seed
& 0:?i
& whl'(1+!i:~>10:?i&out$!randBSD) & out$\nMicrosoft
& 0:?seed
& 0:?i
& whl'(1+!i:~>10:?i&out$!randMS) ) Output: BSD 12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310 Microsoft 38 7719 21238 2437 8855 11797 8365 32285 10450 30612 ## C In a pretended lib style, this code produces a rand() function depends on compiler macro: gcc -DMS_RAND uses MS style, otherwise it's BSD rand by default. #include <stdio.h> /* always assuming int is at least 32 bits */ int rand(); int rseed = 0; inline void srand(int x) { rseed = x; } #ifndef MS_RAND #define RAND_MAX ((1U << 31) - 1) inline int rand() { return rseed = (rseed * 1103515245 + 12345) & RAND_MAX; } #else /* MS rand */ #define RAND_MAX_32 ((1U << 31) - 1) #define RAND_MAX ((1U << 15) - 1) inline int rand() { return (rseed = (rseed * 214013 + 2531011) & RAND_MAX_32) >> 16; } #endif/* MS_RAND */ int main() { int i; printf("rand max is %d\n", RAND_MAX); for (i = 0; i < 100; i++) printf("%d\n", rand()); return 0; }  ## C# Works with: C# version 6+ using System; using System.Collections.Generic; using System.Linq; using static System.Console; namespace LinearCongruentialGenerator { static class LinearCongruentialGenerator { static int _seed = (int)DateTime.Now.Ticks; // from bad random gens might as well have bad seed! static int _bsdCurrent = _seed; static int _msvcrtCurrent = _seed; static int Next(int seed, int a, int b) => (a * seed + b) & int.MaxValue; static int BsdRand() => _bsdCurrent = Next(_bsdCurrent, 1103515245, 12345); static int MscvrtRand() => _msvcrtCurrent = Next (_msvcrtCurrent << 16,214013,2531011) >> 16; static void PrintRandom(int count, bool isBsd) { var name = isBsd ? "BSD" : "MS"; WriteLine($"{name} next {count} Random");
var gen = isBsd ? (Func<int>)(BsdRand) : MscvrtRand;
foreach (var r in Enumerable.Repeat(gen, count))
WriteLine(r.Invoke());
}

static void Main(string[] args)
{
PrintRandom(10, true);
PrintRandom(10, false);
}
}
}


Produces:

BSD next 10 Random
1587930915
19022880
1025044953
1143293854
1642451583
1110934092
773706389
1830436778
1527715739
2072016696
MS next 10 Random
24368
8854
28772
16122
11064
24190
23724
6690
14784
21222


From a Free Cell Deal solution

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace FreeCellDeals
{
public class LCG
{
private int _state;
public bool Microsoft { get; set;}
public bool BSD
{
get
{
return !Microsoft;
}
set
{
Microsoft = !value;
}
}

public LCG(bool microsoft = true)
{
_state = (int)DateTime.Now.Ticks;
Microsoft = microsoft;
}

public LCG(int n, bool microsoft = true)
{
_state = n;
Microsoft = microsoft;
}

public int Next()
{
if (BSD)
{
return _state = (1103515245 * _state + 12345) & int.MaxValue;
}
return ((_state = 214013 * _state + 2531011) & int.MaxValue) >> 16;
}

public IEnumerable<int> Seq()
{
while (true)
{
yield return Next();
}
}
}

class Program
{
static void Main()
{
LCG ms = new LCG(0, true);
LCG bsd = new LCG(0,false);
Console.WriteLine("Microsoft");
ms.Seq().Take(10).ToList().ForEach(Console.WriteLine);
Console.WriteLine("\nBSD");
bsd.Seq().Take(10).ToList().ForEach(Console.WriteLine);
}
}
}


Output:

Microsoft
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

BSD
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310


## C++

#include <iostream>

//--------------------------------------------------------------------------------------------------
using namespace std;

//--------------------------------------------------------------------------------------------------
class mRND
{
public:
void seed( unsigned int s ) { _seed = s; }

protected:
mRND() : _seed( 0 ), _a( 0 ), _c( 0 ), _m( 2147483648 ) {}
int rnd() { return( _seed = ( _a * _seed + _c ) % _m ); }

int _a, _c;
unsigned int _m, _seed;
};
//--------------------------------------------------------------------------------------------------
class MS_RND : public mRND
{
public:
MS_RND()  { _a = 214013; _c = 2531011; }
int rnd() { return mRND::rnd() >> 16; }
};
//--------------------------------------------------------------------------------------------------
class BSD_RND : public mRND
{
public:
BSD_RND() { _a = 1103515245; _c = 12345; }
int rnd() { return mRND::rnd(); }
};
//--------------------------------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
BSD_RND bsd_rnd;
MS_RND ms_rnd;

cout << "MS RAND:" << endl << "========" << endl;
for( int x = 0; x < 10; x++ )
cout << ms_rnd.rnd() << endl;

cout << endl  << "BSD RAND:" << endl << "=========" << endl;
for( int x = 0; x < 10; x++ )
cout << bsd_rnd.rnd() << endl;

cout << endl << endl;
system( "pause" );
return 0;
}
//--------------------------------------------------------------------------------------------------


Output:

MS RAND:
========
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

BSD RAND:
=========
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

C++11
Works with: C++11
#include <iostream>
#include <random>

int main() {

std::linear_congruential_engine<std::uint_fast32_t, 1103515245, 12345, 1 << 31> bsd_rand(0);
std::linear_congruential_engine<std::uint_fast32_t, 214013, 2531011, 1 << 31> ms_rand(0);

std::cout << "BSD RAND:" << std::endl << "========" << std::endl;
for (int i = 0; i < 10; i++) {
std::cout << bsd_rand() << std::endl;
}
std::cout << std::endl;
std::cout << "MS RAND:" << std::endl << "========" << std::endl;
for (int i = 0; i < 10; i++) {
std::cout << (ms_rand() >> 16) << std::endl;
}

return 0;
}


Output:

BSD RAND:
========
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

MS RAND:
========
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## Clojure

(defn iterator [a b]
(fn[x] (mod (+ (* a x) b) (bit-shift-left 1 31))))

(def bsd (drop 1 (iterate (iterator 1103515245 12345) 0)))

(def ms (drop 1 (for [x (iterate  (iterator 214013 2531011) 0)] (bit-shift-right x 16))))

(take 10 bsd) ;-> (12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310)
(take 10 ms) ;-> (38 7719 21238 2437 8855 11797 8365 32285 10450 30612)


## Common Lisp

(defun make-rng (&key (seed 0) (mode nil))
"returns an RNG according to :seed and :mode keywords
default mode: bsd
default seed: 0 (should be 1 actually)"
(if (eql mode 'ms)
#'(lambda ()
(ash (setf seed (mod (+ (* 214013 seed) 2531011) (expt 2 31))) -16))
#'(lambda () (setf seed (mod (+ (* seed 1103515245) 12345) (expt 2 31))))))

(let ((rng (make-rng)))
(dotimes (x 10) (format t "BSD: ~d~%" (funcall rng))))

(let ((rng (make-rng :mode 'ms :seed 1)))
(dotimes (x 10) (format t "MS: ~d~%" (funcall rng))))


Another solution could be:

(defun linear-random (seed &key (times 1) (bounds (expt 2 31)) (multiplier 1103515245) (adder 12345) (divisor 1) (max 2147483647) (min 0))
(loop for candidate = seed then (mod (+ (* multiplier candidate) adder) bounds)
for result = candidate then (floor (/ candidate divisor))
when (and (< result max) (> result min)) collect result into valid-numbers
when (> (length valid-numbers) times) return result))


Which defaults to the BSD formula, but can be customized to any formula with keyword arguments, for example:

(format t "Count:~15tBSD:~30tMS:~%~{~{~a~15t~a~30t~a~%~}~}"
(loop for i from 0 upto 5 collect
(list i
(linear-random 0 :times i)
(linear-random 0 :times i :multiplier 214013 :adder 2531011 :max 32767 :divisor (expt 2 16)))))


Outputs:

Count:         BSD:           MS:
0              12345          38
1              1406932606     7719
2              654583775      21238
3              1449466924     2437
4              229283573      8855
5              1109335178     11797

## D

struct LinearCongruentialGenerator {
enum uint RAND_MAX = (1U << 31) - 1;
uint seed = 0;

uint randBSD() pure nothrow @nogc {
seed = (seed * 1_103_515_245 + 12_345) & RAND_MAX;
return seed;
}

uint randMS() pure nothrow @nogc {
seed = (seed * 214_013 + 2_531_011) & RAND_MAX;
return seed >> 16;
}
}

void main() {
import std.stdio;

LinearCongruentialGenerator rnd;

foreach (immutable i; 0 .. 10)
writeln(rnd.randBSD);
writeln;

rnd.seed = 0;
foreach (immutable i; 0 .. 10)
writeln(rnd.randMS);
}


Output:

12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## dc

dc has no bitwise operations, so this program uses the modulus operator (2147483648 %) and division (65536 /). Fortunately, dc numbers cannot overflow to negative, so the modulus calculation involves only non-negative integers.

For BSD rand():

[*
* lrx -- (random number from 0 to 2147483647)
*
* Returns a number from the BSD rand() sequence.
* Seeded by storing a seed in register R.
*]sz
[lR 1103515245 * 12345 + 2147483648 % d sR]sr

[* Set seed to 1, then print the first 3 random numbers. *]sz
1 sR
lrx psz lrx psz lrx psz
1103527590
377401575
662824084

For Microsoft rand():

[*
* lrx -- (random number from 0 to 32767)
*
* Returns a number from the Microsoft rand() sequence.
* Seeded by storing a seed in register R.
*]sz
[lR 214013 * 2531011 + 2147483648 % d sR 65536 /]sr

[* Set seed to 1, then print the first 3 random numbers. *]sz
1 sR
lrx psz lrx psz lrx psz
41
18467
6334

## Delphi

Translation of: C#
program Linear_congruential_generator;

{$APPTYPE CONSOLE} {$R *.res}

uses
System.SysUtils,
Winapi.Windows;

type
TRandom = record
private
FSeed: Cardinal;
FBsdCurrent: Cardinal;
FMsvcrtCurrent: Cardinal;
class function Next(seed, a, b: Cardinal): Cardinal; static;
public
constructor Create(const seed: Cardinal);
function Rand(Bsd: Boolean = True): Cardinal;
property Seed: Cardinal read FSeed;
end;

{ TRandom }

class function TRandom.Next(seed, a, b: Cardinal): Cardinal;
begin
Result := (a * seed + b) and MAXDWORD;
end;

function TRandom.Rand(Bsd: Boolean): Cardinal;
begin
if Bsd then
begin
FBsdCurrent := Next(FBsdCurrent, 1103515245, 12345);
Result := FBsdCurrent;
end
else
begin
FMsvcrtCurrent := Next(FMsvcrtCurrent shl 16, 214013, 2531011) shr 16;
Result := FMsvcrtCurrent;
end;
end;

constructor TRandom.Create(const seed: Cardinal);
begin
FSeed := seed;
FBsdCurrent := FSeed;
FMsvcrtCurrent := FSeed;
end;

var
r: TRandom;

procedure PrintRandom(count: Integer; IsBsd: Boolean);
const
NAME: array[Boolean] of string = ('MS', 'BSD');
var
i: Integer;
begin
Writeln(NAME[IsBsd], ' next ', count, ' Random'#10);
for i := 0 to count - 1 do
writeln('   ', r.Rand(IsBsd));
writeln;
end;

begin
r.Create(GetTickCount);
PrintRandom(10, True);
PrintRandom(10, False);
end.

Output:
BSD next 10 Random

3076996592
1668591465
978771438
1655648911
3482994972
245356837
1171712762
1870031019
3901807368
2560221857

MS next 10 Random

22925
26495
34217
21291
29349
31799
10113
52643
58173
35439


## EasyLang

func mul32 a b .
# to avoid overflow with 53bit integer precision with double
ah = a div 0x10000
al = a mod 0x10000
bh = b div 0x10000
bl = b mod 0x10000
return al * bl + al * bh * 0x10000 + bl * ah * 0x10000
.
global state_bsd state_ms .
func rand_bsd .
state_bsd = (mul32 1103515245 state_bsd + 12345) mod 0x80000000
return state_bsd
.
func rand_ms .
state_ms = (214013 * state_ms + 2531011) mod 0x80000000
return state_ms div 0x10000
.
for i = 1 to 5
print rand_bsd
.
print ""
for i = 1 to 5
print rand_ms
.
Output:
12345
1406932606
654583775
1449466924
229283573

38
7719
21238
2437
8855


## EDSAC order code

The first version of this solution had trouble with the "sandwich digit". As pointed out by Wilkes, Wheeler & Gill (1951 edition, page 26), a 35-bit constant cannot be loaded via pseudo-orders if the middle bit (sandwich digit) is 1. One workaround, adopted in the EDSAC solution to the Babbage Problem, is to use the negative of the constant instead. The alternative, which WWG evidently preferred and which is used in the LCG solution posted here, is to load 35-bit constants via the library subroutine R9.

The task doesn't specify what random seed is to be used. This program uses 1, with results identical to those from the Elixir program.

 [Linear congruential generators for pseudo-random numbers.
EDSAC program, Initial Orders 2.]

[Library subroutine R9, to read integer constants at load time.
See Wilkes, Wheeler & Gill, 1951 edition, pages 98 & 148.]
..PK
T 56 K [must be loaded at 56]
GKT20FVDL8FA40DUDTFI40FA40FS39FG@S2FG23FA5@T5@E4@

[Modification of library subroutine P7.
Prints non-negative integer, up to 10 digits, right-justified.
Set up to be called with 'G N', so that caller needn't know its address.
See Wilkes, Wheeler & Gill, 1951 edition, page 18.]
T  46 K  [location corresponding to N parameter]
P  72 F  [load subroutine at 72]
E  25 K  TN
H17@S17@A43@G23@UFS43@T1FV4DAFG50@SFLDUFXFOFFFSFL4FT4DA49@T31@
A1FA43@G20@XFP1024FP610D@524D!FO46@O26@XFO46@SFL8FT4DE39@

[BSD linear congruential generator.
Call with 'G B' to initialize, passing seed in 0D.
Call with 'G 1 B' to get next value, returned in 0D.]
T  53 K  [location corresponding to B parameter]
P 140 F  [load subroutine at 140]
E  25 K  TB GK
[0]   G  10 @  [jump to initialize]
[1]   G  15 @  [jump to get next value]
[2]   PF  PF   [mask, 2^31 - 1]
[4]   PF  PF   [multiplier]
[6]   PF  PF   [added constant]
[Call R9 to set the 3 preceding constants at load time.]
E69KT2#@
2147483647F1103515245F12345#
T8Z
[8]   PF  PF    [current state]

[Initialize; caller places seed in 0D]
[10]   A    3 F  [make jump back to caller]
T   14 @  [plant in code]
A      D  [load seed passed by caller]
T    8#@  [store as initial state]
[14]   Z      F  [overwritten by jump back to caller]

[Get next value from BSD; return it in 0D]
[15]   A    3 F  [make jump back to caller]
T   28 @  [plant in code, acc := 0]
H    4#@  [mult reg := multiplier]
V    8#@  [acc := state * multiplier]
LF  LF  L64F  [shift 34 left, done as 13 + 13 + 8]
A    6#@  [add the constant]
T      D  [temp store in 0D]
H    2#@  [mult reg := mask]
C      D  [acc := result modulo 2^31]
U    8#@  [update state]
T      D  [also to 0D for caller]
[28]   Z      F  [overwritten by jump back to caller]

[Microsoft linear congruential generator.
Call with 'G M' to initialize, passing seed in 0D.
Call with 'G 1 M' to get next value, returned in 0D.
Very similar to code for BSD, so given in condensed form.]
T47KP180FE25KTMGKG10@G15@PFPFPFPFPFPFE69KT2#@
2147483647F214013F2531011# [the 3 constants]
[Unlike BSD, MS returns the state divided by 2^16]
RF  RD  [shift 16 right, done as 15 + 1]
T    D  [to 0D for caller]
[30]   Z    F  [overwritten by jump back to caller]

[Main routine]
T  220 K  [load at 220]
G      K  [set theta parameter as usual]
[0]   PF    PF  [35-bit seed]
[Use library subroutine R9 to set seed]
E69K T#@
1#        [non-negative seed followed by '#']
T2Z
[2]   P      F  [negative counter for loop]
[3]   P   10 F  [to print first 10 values]
[Characters for printing]
[4]   B      F
[5]   D      F
[6]   E      F
[7]   M      F
[8]   S      F
[9]   C      F  [colon when in figures mode]
[10]   K 2048 F  [set letters on teleprinter]
[11]   #      F  [set figures on teleprinter]
[12]   @      F  [carriage return]
[13]   &      F  [line feed]
[14]   K 4096 F  [null]

[Enter with acc = 0]
[Print 'SEED:' and then the seed]
[15]   O10@ O8@ O6@ O6@ O5@ O11@ O9@
A     #@  [load seed]
T      D  [store in 0D for printing]
[24]   A   24 @  [pass return address]
G      N  [call print subroutine]
O12@ O13@ [print new line]

[Initialize the BSD generator]
A     #@  [load seed]
T      D  [pass seed in 0D]
[30]   A   30 @  [pass return address]
G      B  [call BSD initializer]
O10@ O4@ O8@ O5@ O11@ O9@ O12@ O13@  [print 'BSD:']
S    3 @  [load negative of count]
[Loop printing values from BSD generator]
[41]   T    2 @  [update negative counter]
[42]   A   42 @  [pass return address]
G    1 B  [call BSD to get next value in 0D]
[44]   A   44 @  [pass return address]
G      N  [call print subroutine]
O12@ O13@ [print new line]
A    2 @  [load negative counter]
A    2 F  [increment]
G   41 @  [loop until counter = 0]

[Microsoft LCG, very similar to BSD, so given in condensed form]
A#@TDA53@GMO10@O7@O8@O11@O9@O12@O13@S3@T2@A64@G1MA66@GNO12@O13@A2@A2FG63@

O   14 @  [print null to flush teleprinter buffer]
Z      F  [stop]
E   15 Z  [define entry point]
P      F  [acc = 0 on entry]
Output:
SEED:          1
BSD:
1103527590
377401575
662824084
1147902781
2035015474
368800899
1508029952
486256185
1062517886
267834847
MS:
41
18467
6334
26500
19169
15724
11478
29358
26962
24464


## Elixir

defmodule LCG do
def ms_seed(seed) do
Process.put(:ms_state, seed)
ms_rand
Process.put(:ms_seed, seed)
end

def ms_rand do
state = Process.get(:ms_state)
state2 = rem(214013 * state + 2531011, 2147483648)
Process.put(:ms_state, state2)
div(state, 65536)
end

def bsd_seed(seed) do
Process.put(:bsd_state, seed)
Process.put(:bsd_seed, seed)
end

def bsd_rand do
state = Process.get(:bsd_state)
state2 = rem(1103515245 * state + 12345, 2147483648)
Process.put(:bsd_state, state2)
state2
end
end

Enum.each([0,1], fn i ->
IO.puts "\nRandom seed: #{i}\n        BSD      MS"
LCG.bsd_seed(i)
LCG.ms_seed(i)
Enum.each(1..10, fn _ ->
:io.format "~11w~8w~n", [LCG.bsd_rand, LCG.ms_rand]
end)
end)

Output:
Random seed: 0
BSD      MS
12345      38
1406932606    7719
654583775   21238
1449466924    2437
229283573    8855
1109335178   11797
1051550459    8365
1293799192   32285
794471793   10450
551188310   30612

Random seed: 1
BSD      MS
1103527590      41
377401575   18467
662824084    6334
1147902781   26500
2035015474   19169
368800899   15724
1508029952   11478
486256185   29358
1062517886   26962
267834847   24464


## Erlang

Translation of: Elixir
-module(lcg).
-export([bsd_seed/1, ms_seed/1, bsd_rand/0, ms_rand/0]).

bsd_seed(Seed) -> put(bsd_state, Seed).
ms_seed(Seed)  -> put(ms_state, Seed).

bsd_rand() ->
State = (get(bsd_state) * 1103515245 + 12345) rem 2147483648,
put(bsd_state,State),
State.

ms_rand() ->
State = (get(ms_state) * 214013 + 2531011) rem 2147483648,
put(ms_state,State),
State div 65536.

main(_) ->
bsd_seed(0),
ms_seed(0),
io:fwrite("~10s~c~5s~n", ["BSD", 9, "MS"]),
lists:map(fun(_) -> io:fwrite("~10w~c~5w~n", [bsd_rand(),9,ms_rand()]) end, lists:seq(1,10)).

Output:
       BSD         MS
12345         38
1406932606       7719
654583775      21238
1449466924       2437
229283573       8855
1109335178      11797
1051550459       8365
1293799192      32285
794471793      10450
551188310      30612

## ERRE

ERRE doesn't generate the proper output from the BSD constants; it uses double-precision floating point, which is not enough for some of the intermediate products: for exact computation you can use MULPREC program. The BSD series deviates starting with the third value (see sample output below).

PROGRAM RNG

!$DOUBLE DIM CARDS%[52] PROCEDURE XRANDOM(SEED->XRND) POW31=2^31 POW16=2^16 SEED=SEED*214013+2531011 SEED=SEED-POW31*INT(SEED/POW31) XRND=INT(SEED/POW16) END PROCEDURE PROCEDURE YRANDOM(SEED->YRND) POW31=2^31 SEED=SEED*1103515245+12345 SEED=SEED-POW31*INT(SEED/POW31) YRND=SEED END PROCEDURE BEGIN PRINT(CHR$(12);)
SEED=0  PRINT("BSD:")
FOR I%=1 TO 10 DO
YRANDOM(SEED->YRND)
PRINT(TAB(10);YRND)
END FOR
SEED=0  PRINT("MSD:")
FOR I%=1 TO 10 DO
XRANDOM(SEED->XRND)
PRINT(TAB(10);XRND)
END FOR
END PROGRAM
Output:
BSD:
12345
1406932606
654583776
405498528
481908312
1397277616
733684288
1620919680
1327744960
1469627648
MSD:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## F#

module lcg =
let bsd seed =
let state = ref seed
(fun (_:unit) ->
state := (1103515245 * !state + 12345) &&& System.Int32.MaxValue
!state)

let ms seed =
let state = ref seed
(fun (_:unit) ->
state := (214013 * !state + 2531011) &&& System.Int32.MaxValue
!state / (1<<<16))

let rndBSD = lcg.bsd 0;;
let BSD=[for n in [0 .. 9] -> rndBSD()];;

let rndMS = lcg.ms 0;;
let MS=[for n in [0 .. 9] -> rndMS()];;

val BSD : int list =
[12345; 1406932606; 654583775; 1449466924; 229283573; 1109335178; 1051550459;
1293799192; 794471793; 551188310]
val MS : int list =
[38; 7719; 21238; 2437; 8855; 11797; 8365; 32285; 10450; 30612]

## Factor

Works with: Factor version 0.98
USING: fry io kernel lists lists.lazy math prettyprint ;

: lcg ( seed a c m quot: ( state -- rand ) -- list )
[ '[ _ * _ + _ mod ] lfrom-by ] [ lmap-lazy cdr ] bi* ; inline

0 1103515245 12345 2147483648 [ ] lcg           ! bsd
0 214013 2531011 2147483648 [ -16 shift ] lcg   ! ms
[ 10 swap ltake [ . ] leach nl ] bi@

Output:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## Forth

1 31 lshift 1- constant MAX-RAND-BSD
1 15 lshift 1- constant MAX-RAND-MS

variable seed                         \ seed variable

: (random) seed @ * + dup seed ! ;    ( -- n)
: BSDrandom MAX-RAND-BSD 12345 1103515245 (random) and ;
: MSrandom MAX-RAND-MS 2531011 214013 (random) 16 rshift and ;

: test-random
1 seed ! cr ." BSD (seed=1)" cr
5 0 do BSDrandom . cr loop
1 seed ! cr ." MS  (seed=1)" cr
5 0 do MSrandom . cr loop
;

test-random


Output:

BSD (seed=1)
1103527590
377401575
662824084
1147902781
2035015474

MS  (seed=1)
41
18467
6334
26500
19169

## Fortran

Works with: Fortran version 90 and later
module lcgs
implicit none

integer, parameter :: i64 = selected_int_kind(18)
integer, parameter :: a1 = 1103515245, a2 = 214013
integer, parameter :: c1 = 12345, c2 = 2531011
integer, parameter :: div = 65536
integer(i64), parameter :: m = 2147483648_i64  ! need to go to 64 bits because
! of the use of signed integers
contains

function bsdrand(seed)
integer :: bsdrand
integer, optional, intent(in) :: seed
integer(i64) :: x = 0

if(present(seed)) x = seed
x = mod(a1 * x + c1, m)
bsdrand = x
end function

function msrand(seed)
integer :: msrand
integer, optional, intent(in) :: seed
integer(i64) :: x = 0

if(present(seed)) x = seed
x = mod(a2 * x + c2, m)
msrand = x / div
end function
end module

program lcgtest
use lcgs
implicit none
integer :: i

write(*, "(a)") "      BSD            MS"
do i = 1, 10
write(*, "(2i12)") bsdrand(), msrand()
end do
end program


Output

      BSD            MS
12345          38
1406932606        7719
654583775       21238
1449466924        2437
229283573        8855
1109335178       11797
1051550459        8365
1293799192       32285
794471793       10450
551188310       30612

## FreeBASIC

' version 04-11-2016
' compile with: fbc -s console

' to seed BSD_lcg(seed > -1)
' to get random number BSD_lcg(-1) or BSD_lcg() or just BSD_lcg
Function BSD_lcg(seed As UInteger = -1) As UInteger

Static As UInteger bsd_state

If seed <> -1 Then
bsd_state = seed Mod 2 ^ 31
Else
bsd_state = (1103515245 * bsd_state + 12345) Mod 2 ^ 31
End If

Return bsd_state

End Function

' to seed ms_lcg(seed > -1)
' to get random number ms_lcg(-1) or ms_lcg() or just ms_lcg
Function ms_lcg(seed As Integer = -1) As UInteger

Static As UInteger ms_state

If seed <> -1 Then
ms_state = seed Mod 2 ^ 31
Else
ms_state = (214013 * ms_state + 2531011) Mod 2 ^ 31
End If

Return ms_state Shr 16

End Function

' ------=< MAIN >=------

Dim As Long i

Print "MS generator"
' ms_lcg(0)      ' state = 0 at the start of the program
For i = 1 To 10
Print Using "###########"; ms_lcg
Next

Print
Print "BSD generator"
' BSD_lcg(0)     ' state = 0 at the start of the program
For i  = 1 To 10
Print Using "###########"; BSD_lcg
Next

' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End
Output:
MS generator
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

BSD generator
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

## Fōrmulæ

Fōrmulæ programs are not textual, visualization/edition of programs is done showing/manipulating structures but not text. Moreover, there can be multiple visual representations of the same program. Even though it is possible to have textual representation —i.e. XML, JSON— they are intended for storage and transfer purposes more than visualization and edition.

Programs in Fōrmulæ are created/edited online in its website.

In this page you can see and run the program(s) related to this task and their results. You can also change either the programs or the parameters they are called with, for experimentation, but remember that these programs were created with the main purpose of showing a clear solution of the task, and they generally lack any kind of validation.

Solution

Definitions

Test case

## Go

package main

import "fmt"

// basic linear congruential generator
func lcg(a, c, m, seed uint32) func() uint32 {
r := seed
return func() uint32 {
r = (a*r + c) % m
return r
}
}

// microsoft generator has extra division step
func msg(seed uint32) func() uint32 {
g := lcg(214013, 2531011, 1<<31, seed)
return func() uint32 {
return g() / (1 << 16)
}
}

func example(seed uint32) {
fmt.Printf("\nWith seed = %d\n", seed)
bsd := lcg(1103515245, 12345, 1<<31, seed)
msf := msg(seed)
fmt.Println("       BSD  Microsoft")
for i := 0; i < 5; i++ {
fmt.Printf("%10d    %5d\n", bsd(), msf())
}
}

func main() {
example(0)
example(1)
}


Output:

With seed = 0
BSD  Microsoft
12345       38
1406932606     7719
654583775    21238
1449466924     2437
229283573     8855

With seed = 1
BSD  Microsoft
1103527590       41
377401575    18467
662824084     6334
1147902781    26500
2035015474    19169


bsd = tail . iterate (\n -> (n * 1103515245 + 12345) mod 2^31)
msr = map (div 2^16) . tail . iterate (\n -> (214013 * n + 2531011) mod 2^31)

main = do
print $take 10$ bsd 0 -- can take seeds other than 0, of course
print $take 10$ msr 0


## Icon and Unicon

The following LCRNG's behave in the same way maintaining the state (seed) from round to round. There is an srand procedure for each lcrng that maintains the seed state and allows the user to assign a new state.

link printf

procedure main()
printf("       BSD        MS\n")
every 1 to 10 do
printf("%10s %10s\n",rand_BSD(),rand_MS())
end

procedure srand_BSD(x)             #: seed random
static seed
return seed := \x | \seed | 0   # parm or seed or zero if none
end

procedure rand_BSD()               #: lcrng
return srand_BSD((1103515245 * srand_BSD() + 12345) % 2147483648)
end

procedure srand_MS(x)              #: seed random
static seed
return seed := \x | \seed | 0   # parm or seed or zero if none
end

procedure rand_MS()                #: lcrng
return ishift(srand_MS((214013 * srand_MS() + 2531011) % 2147483648),-16)
end


## J

Solution:

lcg=: adverb define
0 m lcg y                     NB. default seed of 0
:
'a c mod'=. x: m
}. (mod | c + a * ])^:(<y+1) x
)

rand_bsd=: (1103515245 12345 , <.2^31) lcg
rand_ms=: (2^16) <.@:%~ (214013 2531011 , <.2^31) lcg


Example Use:

   rand_bsd 10
12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310
654583775 rand_bsd 4
1449466924 229283573 1109335178 1051550459
rand_ms 10
38 7719 21238 2437 8855 11797 8365 32285 10450 30612
1 rand_ms 5                  NB. seed of 1
41 18467 6334 26500 19169


## Java

Works with: Java version 8
import java.util.stream.IntStream;
import static java.util.stream.IntStream.iterate;

public class LinearCongruentialGenerator {
final static int mask = (1 << 31) - 1;

public static void main(String[] args) {
System.out.println("BSD:");
randBSD(0).limit(10).forEach(System.out::println);

System.out.println("\nMS:");
randMS(0).limit(10).forEach(System.out::println);
}

static IntStream randBSD(int seed) {
return iterate(seed, s -> (s * 1_103_515_245 + 12_345) & mask).skip(1);
}

static IntStream randMS(int seed) {
return iterate(seed, s -> (s * 214_013 + 2_531_011) & mask).skip(1)
.map(i -> i >> 16);
}
}

BSD:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

MS:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## jq

The Go implementation of jq (gojq) supports unlimited-precision integer arithmetic and therefore linear congruential generators (LCGs) can be trivially written for gojq.

The C implementation of jq, however, currently uses IEEE 754 64-bit numbers for arithmetic, so a BSD generator for the C implementation of jq would require some kind of "big integer" support.

In this entry, therefore, we first present functions for the Microsoft LCG that can be used with jq or gojq, and then present functions to support the BSD generator on the assumption that a suitable "BigInt" library is available.

#### Microsoft LCG

# 15-bit integers generated using the same formula as rand()
# from the Microsoft C Runtime.
# Input: [ count, state, rand ]
def next_rand_Microsoft:
.[0] as $count | .[1] as$state
| ( (214013 * $state) + 2531011) % 2147483648 # mod 2^31 | [$count+1 , ., (. / 65536 | floor) ];

# Generate the first n pseudo-random numbers:
def rand_Microsoft(seed; n):
[0,seed]
| next_rand_Microsoft  # the seed is not so random
| recurse(if .[0] < n then next_rand_Microsoft else empty end)
| .[2];

Example:

rand_Microsoft(1;5)

Output:
41
18467
6334
26500
19169


#### BSD LCG

The following code has been tested with the "BigInt" library at [1].

# BSD rand()
# Input: [count, previous]
def next_rand_berkeley:
long_multiply("1103515245" ; .[1]|tostring) as $lm | long_add($lm; "12345") as $la # mod 2^31 | [.[0] + 1, (long_mod($la; "2147483648") | tonumber) ];

# Generate n values
def rand_berkeley(seed; n):
[0, seed]
| next_rand_berkeley # skip the seed itself
| recurse(if .[0] < n then next_rand_berkeley else empty end)
| .[1];

Example:

rand_berkeley(1;5)

Output:
1103527590
377401575
662824084
1147902781
2035015474


## Julia

getlgc creates a linear congruential generator as a closure. This function is used to create the two generators called for by the task.

using Printf

function getlgc(r::Integer, a::Integer, c::Integer, m::Integer, sh::Integer)
state = r
return function lgcrand()
state = mod(a * state + c, m)
return state >> sh
end
end

seed, nrep = 0, 10
bsdrand = getlgc(seed, 1103515245, 12345, 2 ^ 31, 0)

println("The first $nrep results for a BSD rand seeded with$seed:")
for _ in 1:nrep
@printf("%14d\n", bsdrand())
end

msrand = getlgc(seed, 214013, 2531011, 2 ^ 31, 16)

println("\nThe first $nrep results for a M\$ rand seeded with $seed:") for _ in 1:nrep @printf("%14d\n", msrand()) end  Output: The first 10 results for a BSD rand seeded with 0: 12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310 The first 10 results for a M$ rand seeded with 0:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## K

   bsd:{1_ y{((1103515245*x)+12345)!(_2^31)}\x}
ms:{1_(y{_(((214013*x)+2531011)!(_2^31))}\x)%(_2^16)}

bsd[0;10]
12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310
ms[0;10]
38 7719 21238 2437 8855 11797 8365 32285 10450 30612


## Kotlin

// version 1.1.3

class Lcg(val a: Long, val c: Long, val m: Long, val d: Long, val s: Long) {
private var state = s

fun nextInt(): Long {
state = (a * state + c) % m
return state / d
}
}

fun main(args: Array<String>) {
println("First 10 BSD random numbers - seed 0")
val bsd = Lcg(1103515245, 12345, 1 shl 31, 1, 0)
for (i in 1..10) println("${bsd.nextInt()}") println("\nFirst 10 MSC random numbers - seed 0") val msc = Lcg(214013, 2531011, 1 shl 31, 1 shl 16, 0) for (i in 1..10) println("${msc.nextInt()}")
}

Output:
First 10 BSD random numbers - seed 0
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

First 10 MSC random numbers - seed 0
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## Liberty BASIC

'by default these are 0
global BSDState
global MSState

for i = 1 to 10
print randBSD()
next i

print

for i = 1 to 10
print randMS()
next i

function randBSD()
randBSD = (1103515245 * BSDState + 12345) mod (2 ^ 31)
BSDState = randBSD
end function

function randMS()
MSState = (214013 * MSState + 2531011) mod (2 ^ 31)
randMS = int(MSState / 2 ^ 16)
end function

## Logo

Note that, perhaps ironically, UCB Logo, as of version 6.0, doesn't generate the proper output from the BSD constants; it uses double-precision floating point, which is not enough for some of the intermediate products. In UCBLogo, the BSD series deviates starting with the third value (see sample output below).

; Configuration parameters for Microsoft and BSD implementations
make "LCG_MS [214013 2531011 65536 2147483648]
make "LCG_BSD [1103515245 12345 1 2147483648]

; Default seed is 0
make "_lcg_value 0

; set the seed
to lcg_seed :seed
make "_lcg_value :seed
end

; generate the next number in the series using the given parameters
to lcg_rand [:config :LCG_MS]
local "a local "c local "d local "m
foreach [a c d m] [
make ? item # :config
]
make "_lcg_value (modulo (sum (product :a :_lcg_value) :c) :m)
output int quotient :_lcg_value :d
end

foreach (list :LCG_BSD :LCG_MS) [
lcg_seed 0
repeat 10 [
print (lcg_rand ?)
]
print []
]
bye

Output:

12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

38
7719
21238
2437
8855
11797
8365
32285
10450
30612


UCBLogo output for the BSD section:

12345
1406932606
654583808
1358247936
2138638336
1459132416
1445521408
370866176
1896597568
1518859008

## Lua

Works with: Lua version 5.3

This requires Lua 5.3 or later because previous versions didn't have support for large integers or integral arithmetic operations.

local RNG = {
new = function(class, a, c, m, rand)
local self = setmetatable({}, class)
local state = 0
self.rnd = function()
state = (a * state + c) % m
return rand and rand(state) or state
end
self.seed = function(new_seed)
state = new_seed % m
end
return self
end
}

bsd = RNG:new(1103515245, 12345, 1<<31)
ms = RNG:new(214013, 2531011, 1<<31, function(s) return s>>16 end)

print"BSD:"
for _ = 1,10 do
print(("\t%10d"):format(bsd.rnd()))
end
print"Microsoft:"
for _ = 1,10 do
print(("\t%10d"):format(ms.rnd()))
end

Output:
BSD:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310
Microsoft:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## Mathematica/Wolfram Language

BSDrand[x_] := Mod[x*1103515245 + 12345, 2147483648]
NestList[BSDrand, 0, 10]
-> {0, 12345, 1406932606, 654583775, 1449466924, 229283573, 1109335178, 1051550459, 1293799192, 794471793, 551188310}

MSrand[x_] := Mod[x*214013 + 2531011, 2147483648]
BitShiftRight[ NestList[MSrand, 0, 10], 16]
-> {0, 38, 7719, 21238, 2437, 8855, 11797, 8365, 32285, 10450, 30612}


## Maxima

seed: 0$ms_rand() := quotient(seed: mod(214013 * seed + 2531011, 2147483648), 65536)$
makelist(ms_rand(), 20); /* see http://oeis.org/A096558 */

[38, 7719, 21238, 2437, 8855, 11797, 8365, 32285, 10450, 30612, 5853, 28100, 1142, 281,
20537, 15921, 8945, 26285, 2997, 14680]

seed: 0$bsd_rand() := seed: mod(1103515245 * seed + 12345, 2147483648)$
makelist(bsd_rand(), 20); /* see http://www.randomwalk.de/scimath/prngseqs.txt */

[12345, 1406932606, 654583775, 1449466924, 229283573, 1109335178, 1051550459,
1293799192, 794471793, 551188310, 803550167, 1772930244, 370913197, 639546082, 1381971571,
1695770928, 2121308585, 1719212846, 996984527, 1157490780]


## Nim

proc bsdRand(seed: int): iterator: int =
var state = seed
result = iterator: int =
while true:
state = (1_103_515_245 * state + 12_345) and 0x7fffffff
yield state

proc msvcrtRand(seed: int): iterator: int =
var state = seed
result = iterator: int =
while true:
state = (214_013 * state + 2_531_011) and 0x7fffffff
yield state shr 16

echo "BSD with seed = 1 (OEIS A096553):"
var count = 0
let iter1 = bsdRand(1)
for val in iter1():
echo val
inc count
if count == 10:
break

echo ""
echo "Microsoft with seed = 0 (OEIS A096558):"
count = 0
let iter2 = msvcrtRand(0)
for val in iter2():
echo val
inc count
if count == 10:
break

Output:
BSD with seed = 1 (OEIS A096553):
1103527590
377401575
662824084
1147902781
2035015474
368800899
1508029952
486256185
1062517886
267834847

Microsoft with seed = 0 (OEIS A096558):
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

## OCaml

let lcg31 a c x =
(a * x + c) land 0x7fffffff

let rng_seq rng seed =
Seq.iterate rng (rng seed)

let lcg_bsd =
rng_seq (lcg31 1103515245 12345)

let lcg_ms seed =
Seq.map (fun r -> r lsr 16) (rng_seq (lcg31 214013 2531011) seed)

(* test code *)
let () =
let print_first8 sq =
sq |> Seq.take 8 |> Seq.map string_of_int
|> List.of_seq |> String.concat " " |> print_endline
in
List.iter print_first8 [lcg_bsd 0; lcg_bsd 1; lcg_ms 0; lcg_ms 1]

Output:
12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192
1103527590 377401575 662824084 1147902781 2035015474 368800899 1508029952 486256185
38 7719 21238 2437 8855 11797 8365 32285
41 18467 6334 26500 19169 15724 11478 29358


## Oforth

Function genLCG returns a block object that, when performed, will return the next random number from the LCG.

: genLCG(a, c, m, seed)
| ch |
Channel newSize(1) dup send(seed) drop ->ch
#[ ch receive a * c + m mod dup ch send drop ] ;
Output:
genLCG(1103515245, 12345, 2 31 pow asInteger, 0) #[ dup perform println ] times(10) drop
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

genLCG(214013, 2531011, 2 31 pow asInteger, 0) #[ dup perform 65536 / println ] times(10) drop
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## PARI/GP

Note that up to PARI/GP version 2.4.0, random() used a linear congruential generator.

BSDseed=Mod(1,1<<31);
MSFTseed=Mod(1,1<<31);
BSD()=BSDseed=1103515245*BSDseed+12345;lift(BSDseed);
MSFT()=MSFTseed=214013*MSFTseed+2531011;lift(MSFTseed)%(1<<31);

## Pascal

Program LinearCongruentialGenerator(output);
{$mode iso} var x1, x2: int64; function bsdrand: cardinal; const a = 1103515245; c = 12345; m = 2147483648; begin x1 := (a * x1 + c) mod m; bsdrand := x1; end; function msrand: cardinal; const a = 214013; c = 2531011; m = 2147483648; begin x2 := (a * x2 + c) mod m; msrand := x2 div 65536; end; var i: cardinal; begin writeln(' BSD MS'); x1 := 0; x2 := 0; for i := 1 to 10 do writeln(bsdrand:12, msrand:12); end.  Output:  BSD MS 12345 38 1406932606 7719 654583775 21238 1449466924 2437 229283573 8855 1109335178 11797 1051550459 8365 1293799192 32285 794471793 10450 551188310 30612 ## Perl Creates a magic scalar whose value is next in the LCG sequence when read. use strict; package LCG; use overload '0+' => \&get; use integer; sub gen_bsd { (1103515245 * shift() + 12345) % (1 << 31) } sub gen_ms { my$s = (214013 * shift() + 2531011) % (1 << 31);
$s,$s / (1 << 16)
}

sub set { $_[0]->{seed} =$_[1] } # srand
sub get {
my $o = shift; ($o->{seed}, my $r) =$o->{meth}->($o->{seed});$r //= $o->{seed} } sub new { my$cls = shift;
my %opts = @_;
bless {
seed => $opts{seed}, meth =>$opts{meth} eq 'MS' ? \&gen_ms : \&gen_bsd,
}, ref $cls ||$cls;
}

package main;

my $rand = LCG->new; print "BSD:\n"; print "$rand\n" for 1 .. 10;

$rand = LCG->new(meth => 'MS'); print "\nMS:\n"; print "$rand\n" for 1 .. 10;


output

BSD:
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

MS:
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## Phix

Library: Phix/mpfr

As per the comments, I had to resort to gmp to get BSDrnd() to work on 32-bit.

with javascript_semantics
atom seed

include builtins/mpfr.e

function BSDrnd()
-- oh dear, native only works on 64-bit,
-- as per ERRE and UCBLogo above on 32-bit...
--  seed = remainder(1103515245 * seed + 12345, #8000_0000)
-- so, resort to gmp, with the added twist than both
-- 1103515245 and #8000_0000 are greater than 1GB and
-- therefore a smidge too big & need some extra help...
mpz z = mpz_init(seed),
m9 = mpz_init("1103515245"),
h8 = mpz_init("0x80000000")
mpz_mul(z,z,m9)
mpz_fdiv_r(z,z,h8)
seed = mpz_get_atom(z)
return seed
end function

function MSrnd()
seed = and_bits(seed*214013+2531011,#7FFFFFFF)
return floor(seed/power(2,16))
end function

seed = 0
?"BSDrnd"
for i=1 to 10 do printf(1,"%d\n",BSDrnd()) end for
seed = 0
?"MSrnd"
for i=1 to 10 do printf(1,"%d\n",MSrnd()) end for

Output:
"BSDrnd"
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310
"MSrnd"
38
7719
21238
2437
8855
11797
8365
32285
10450
30612


## PHP

Works with: PHP version 5.3+
<?php
function bsd_rand($seed) { return function() use (&$seed) {
return $seed = (1103515245 *$seed + 12345) % (1 << 31);
};
}

function msvcrt_rand($seed) { return function() use (&$seed) {
return ($seed = (214013 *$seed + 2531011) % (1 << 31)) >> 16;
};
}

$lcg = bsd_rand(0); echo "BSD "; for ($i = 0; $i < 10;$i++)
echo $lcg(), " "; echo "\n";$lcg = msvcrt_rand(0);
echo "Microsoft ";
for ($i = 0;$i < 10; $i++) echo$lcg(), " ";
echo "\n";
?>


## Picat

### Methods as hard coded predicates

go =>

% BSD
println(bsd=[bsd() : _ in 1..10]),
bsd_seed(1),
println(bsd2=[bsd() : _ in 1..10]),

% MS
println(ms=[ms() : _ in 1..10]),
ms_seed(1),
println(ms2=[ms() : _ in 1..10]),

nl.

% BSD
bsd_seed(Seed) =>
get_global_map().put(bsd_state, Seed).
bsd = Rand =>
M = get_global_map(),
Seed = cond(M.has_key(bsd_state), M.get(bsd_state),0),
Rand = (1103515245*Seed + 12345) mod 2**31,
M.put(bsd_state,Rand).

% Microsoft
ms_seed(Seed) =>
get_global_map().put(ms_state, Seed).
ms = Rand div 2**16 =>
M = get_global_map(),
Seed = cond(M.has_key(ms_state),M.get(ms_state),0),
Rand = ((214013*Seed + 2531011) mod 2**31),
M.put(ms_state,Rand).
Output:
bsd = [12345,1406932606,654583775,1449466924,229283573,1109335178,1051550459,1293799192,794471793,551188310]
bsd2 = [1103527590,377401575,662824084,1147902781,2035015474,368800899,1508029952,486256185,1062517886,267834847]
ms = [38,7719,21238,2437,8855,11797,8365,32285,10450,30612]
ms2 = [41,18467,6334,26500,19169,15724,11478,29358,26962,24464]

### Generalized version

Using a global global map for setting/setting seeds etc.

go2 =>

% BSD
lcg_init(bsd,1103515245,12345,2**31,1),
println([lcg(bsd) : _ in 1..10]),

lcg_init(bsd,1,1103515245,12345,2**31,1),
println([lcg(bsd) : _ in 1..10]),

% MS
lcg_init(ms,214013,2531011,2**31,2**16),
println([lcg(ms) : _ in 1..10]),

lcg_init(ms,1,214013,2531011,2**31,2**16),
println([lcg(ms) : _ in 1..10]),

% unknown (-> error)
println([lcg(unknown) : _ in 1..10]),

nl.

% default seed is 0

get_global_map().put(Type,

lcg(Type) = Rand div M.get(outputDivisor) =>
if not get_global_map().has_key(Type) then
throw $lcg(Type,unknown_LCG_type) end, M = get_global_map().get(Type), Rand = ((M.get(multiplier)*M.get(seed) + M.get(adder)) mod M.get(mod)), M.put(seed,Rand), get_global_map().put(Type,M). Output: [12345,1406932606,654583775,1449466924,229283573,1109335178,1051550459,1293799192,794471793,551188310] [1103527590,377401575,662824084,1147902781,2035015474,368800899,1508029952,486256185,1062517886,267834847] [38,7719,21238,2437,8855,11797,8365,32285,10450,30612] [41,18467,6334,26500,19169,15724,11478,29358,26962,24464] *** lcg(unknown,unknown_LCG_type) ## PicoLisp (zero *BsdSeed *MsSeed) (de bsdRand () (setq *BsdSeed (& (+ 12345 (* 1103515245 *BsdSeed)) (dec (** 2 31))) ) ) (de msRand () (>> 16 (setq *MsSeed (& (+ 2531011 (* 214013 *MsSeed)) (dec (** 2 31))) ) ) ) Output: : (do 7 (printsp (bsdRand))) 12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 -> 1051550459 : (do 12 (printsp (msRand))) 38 7719 21238 2437 8855 11797 8365 32285 10450 30612 5853 28100 -> 28100 ## PL/I (nofixedoverflow, nosize): LCG: procedure options (main); declare i fixed binary; put skip list ('BSD', 'MS'); do i = 1 to 20; put skip list (BSD(), MS()); end; bsd: procedure returns (fixed binary (31)); declare const fixed binary static initial (12345); declare s fixed binary (31) static initial (123456789); s = s * 1103515245 + const; s = isrl(isll(s,1), 1); return (s); end bsd; ms: procedure returns (fixed binary (15)); declare const fixed binary (31) static initial (2531011); declare s fixed binary (31) static initial (123456789); s = s * 214013 + const; s = isrl(isll(s,1), 1); return (isrl(s,16)); end ms; end LCG;  OUTPUT: BSD MS 231794730 13259 1126946331 26974 1757975480 13551 850994577 30354 1634557174 18709 707246327 15861 1397699428 16906 1035569613 21981 1904890498 8603 1335160211 12911 1434329552 18110 1273099721 3228 1250890958 27918 1016516591 17989 1097566972 22768 436938117 23599 1175171034 7712 1059748875 15601 308566760 7038 534615297 21512  ## PowerShell Function msstate{ Param($current_seed)
Return (214013*$current_seed+2531011)%2147483648} Function randMS{ Param($MSState)
Return [int]($MSState/65536)} Function randBSD{ Param($BSDState)
Return (1103515245*$BSDState+12345)%2147483648} Write-Host "MS: seed=0"$seed=0 #initialize seed
For($i=1;$i-le5;$i++){$seed = msstate($seed)$rand = randMS($seed) Write-Host$rand}

Write-Host "BSD: seed=0"
$seed=0 #initialize seed For($j=1;$j-le5;$j++){
$seed = randBSD($seed)
Write-Host $seed}  Output: MS: seed=0 39 7720 21238 2437 8855 BSD: seed=0 12345 1406932606 654583775 1449466924 229283573  ## PureBasic Procedure ms_LCG(seed.q = -1) Static state.q If seed >= 0 state = seed Else state = (state * 214013 + 2531011) % (1 << 31) ProcedureReturn state >> 16 EndIf EndProcedure Procedure.q bsd_LCG(seed.q = -1) Static state.q If seed >= 0 state = seed Else state = (state * 1103515245 + 12345) % (1 << 31) ProcedureReturn state EndIf EndProcedure If OpenConsole() Define i PrintN("BSD (seed = 1)") bsd_LCG(1) For i = 1 To 5 PrintN(Str(bsd_LCG())) Next PrintN(#CRLF$ + "MS (seed = 1)")
ms_LCG(1)
For i = 1 To 5
PrintN(Str(ms_LCG()))
Next

Print(#CRLF$+ #CRLF$ + "Press ENTER to exit"): Input()
CloseConsole()
EndIf

Sample output:

BSD (seed = 1)
1103527590
377401575
662824084
1147902781
2035015474

MS (seed = 1)
41
18467
6334
26500
19169

## Python

def bsd_rand(seed):
def rand():
rand.seed = (1103515245*rand.seed + 12345) & 0x7fffffff
return rand.seed
rand.seed = seed
return rand

def msvcrt_rand(seed):
def rand():
rand.seed = (214013*rand.seed + 2531011) & 0x7fffffff
return rand.seed >> 16
rand.seed = seed
return rand

Works with: Python version 3.x
def bsd_rand(seed):
def rand():
nonlocal seed
seed = (1103515245*seed + 12345) & 0x7fffffff
return seed
return rand

def msvcrt_rand(seed):
def rand():
nonlocal seed
seed = (214013*seed + 2531011) & 0x7fffffff
return seed >> 16
return rand


## Quackery

  [ number$10 over size - space swap of swap join echo$ ]  is echonum  ( n -->   )

[ stack 0 ]          is BSD-seed (   --> n )

[ BSD-seed take
1103515245 *
12345 +
hex 7FFFFFFF &
dup BSD-seed put ] is BSD-rand (   --> n )

[ stack 0 ]          is MCR-seed (   --> n )

[ MCR-seed take
214013 *
2531011 +
hex 7FFFFFFF &
dup MCR-seed put
16 >> ]            is MCR-rand (   --> n )

say "  BSD-rand  MCR-rand" cr
10 times
[ BSD-rand echonum
MCR-rand echonum cr ]
Output:
  BSD-rand  MCR-rand
12345        38
1406932606      7719
654583775     21238
1449466924      2437
229283573      8855
1109335178     11797
1051550459      8365
1293799192     32285
794471793     10450
551188310     30612


## R

library(gmp) # for big integers

rand_BSD <- function(n = 1) {
a <- as.bigz(1103515245)
c <- as.bigz(12345)
m <- as.bigz(2^31)
x <- rep(as.bigz(0), n)
x[1] <- (a * as.bigz(seed) + c) %% m
i <- 1
while (i < n) {
x[i+1] <- (a * x[i] + c) %% m
i <- i + 1
}
as.integer(x)
}

seed <- 0
rand_BSD(10)
##  [1]      12345 1406932606  654583775 1449466924  229283573 1109335178
##  [7] 1051550459 1293799192  794471793  551188310

rand_MS <- function(n = 1) {
a <- as.bigz(214013)
c <- as.bigz(2531011)
m <- as.bigz(2^31)
x <- rep(as.bigz(0), n)
x[1] <- (a * as.bigz(seed) + c) %% m
i <- 1
while (i < n) {
x[i+1] <- (a * x[i] + c) %% m
i <- i + 1
}
as.integer(x / 2^16)
}

seed <- 0
rand_MS(10)
##  [1]    38  7719 21238  2437  8855 11797  8365 32285 10450 30612


## Racket

The following solution uses generators and transcribes the mathematical formulas above directly. It does not attempt to be efficient.

#lang racket
(require racket/generator)

(define (bsd-update state_n)
(modulo (+ (* 1103515245 state_n) 12345)
(expt 2 31)))

(define (ms-update state_n)
(modulo (+ (* 214013 state_n) 2531011)
(expt 2 31)))

(define ((rand update ->rand) seed)
(generator ()
(let loop ([state_n seed])
(define state_n+1 (update state_n))
(yield (->rand state_n+1))
(loop state_n+1))))

(define bsd-rand (rand bsd-update identity))
(define ms-rand (rand ms-update (λ (x) (quotient x (expt 2 16)))))


## Raku

(formerly Perl 6)

We'll define subroutines implementing the LCG algorithm for each version. We'll make them return a lazy list.

constant modulus = 2**31;
sub bsd  {
$^seed, ( 1103515245 * * + 12345 ) % modulus ... * } sub ms { map * +> 16, ($^seed, ( 214013 * * + 2531011 ) % modulus ... *
)
}

say 'BSD LCG first 10 values (first one is the seed):';
.say for bsd(0)[^10];

say "\nMS LCG first 10 values (first one is the seed):";
.say for ms(0)[^10];

BSD LCG first 10 values (first one is the seed):
0
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793

MS LCG first 10 values (first one is the seed):
0
38
7719
21238
2437
8855
11797
8365
32285
10450

## REXX

/*REXX program uses a linear congruential generator (LCG)  that simulates the old  BSD  */
/*──────── and MS random number generators:    BSD= 0──►(2^31)-1     MS= 0──►(2^16)-1   */
numeric digits 20                                /*use enough dec. digs for the multiply*/
two@@16= 2**16                                   /*use a variable to contain  2^16      */
two@@31= 2**31                                   /* "  "     "     "    "     2^32      */

do seed=0  for 2;       bsd= seed        /*perform for seed=0  and also  seed=1.*/
ms= seed        /*assign  SEED  to  two REXX variables.*/
say center(' seed='seed" ", 79, '─')     /*display the seed in a title/separator*/
/* [↓]  show 20 rand #'s for each seed.*/
do j=1  for 20                       /*generate & display 20 random numbers.*/

bsd = (1103515245 * bsd   +     12345)   //    two@@31
ms  = (    214013 *  ms   +   2531011)   //    two@@31
/*  ↑                                  */
/*  └─────◄──── REXX remainder operator*/

say '  state'   right(j,3)   " BSD"   right(bsd,     11)   left('', 13),
" MS"    right( ms,     11)   left('',  5),
" rand"  right(ms % two@@16,  6)
end   /*j*/
end       /*seed*/                       /*stick a fork in it,  we're all done. */

output     (shown at five-sixth size.)
─────────────────────────────────── seed=0 ────────────────────────────────────
state   1  BSD       12345                MS     2531011        rand     38
state   2  BSD  1406932606                MS   505908858        rand   7719
state   3  BSD   654583775                MS  1391876949        rand  21238
state   4  BSD  1449466924                MS   159719620        rand   2437
state   5  BSD   229283573                MS   580340855        rand   8855
state   6  BSD  1109335178                MS   773150046        rand  11797
state   7  BSD  1051550459                MS   548247209        rand   8365
state   8  BSD  1293799192                MS  2115878600        rand  32285
state   9  BSD   794471793                MS   684884587        rand  10450
state  10  BSD   551188310                MS  2006221698        rand  30612
state  11  BSD   803550167                MS   383622205        rand   5853
state  12  BSD  1772930244                MS  1841626636        rand  28100
state  13  BSD   370913197                MS    74896543        rand   1142
state  14  BSD   639546082                MS    18439398        rand    281
state  15  BSD  1381971571                MS  1345953809        rand  20537
state  16  BSD  1695770928                MS  1043415696        rand  15921
state  17  BSD  2121308585                MS   586225427        rand   8945
state  18  BSD  1719212846                MS  1722639754        rand  26285
state  19  BSD   996984527                MS   196417061        rand   2997
state  20  BSD  1157490780                MS   962080852        rand  14680
─────────────────────────────────── seed=1 ────────────────────────────────────
state   1  BSD  1103527590                MS     2745024        rand     41
state   2  BSD   377401575                MS  1210316419        rand  18467
state   3  BSD   662824084                MS   415139642        rand   6334
state   4  BSD  1147902781                MS  1736732949        rand  26500
state   5  BSD  2035015474                MS  1256316804        rand  19169
state   6  BSD   368800899                MS  1030492215        rand  15724
state   7  BSD  1508029952                MS   752224798        rand  11478
state   8  BSD   486256185                MS  1924036713        rand  29358
state   9  BSD  1062517886                MS  1766988168        rand  26962
state  10  BSD   267834847                MS  1603301931        rand  24464
state  11  BSD   180171308                MS   373929026        rand   5705
state  12  BSD   836760821                MS  1844513277        rand  28145
state  13  BSD   595337866                MS  1525789900        rand  23281
state  14  BSD   790425851                MS  1102819423        rand  16827
state  15  BSD  2111915288                MS   652855718        rand   9961
state  16  BSD  1149758321                MS    32201169        rand    491
state  17  BSD  1644289366                MS   196285776        rand   2995
state  18  BSD  1388290519                MS   782671571        rand  11942
state  19  BSD  1647418052                MS   316395082        rand   4827
state  20  BSD  1675546029                MS   356309989        rand   5436


## RPL

≪ #1103515245d STATE * #12345d + #2147483647d AND
DUP 'STATE' STO B→R
≫ '?BSD' STO

≪ #214013d STATE * #2531011d + #2147483647d AND
DUP 'STATE' STO SRB SRB B→R
≫ '?MS' STO

≪ { } 0 'STATE' STO
1 5 START OVER EVAL + NEXT
SWAP DROP
≫ 'TEST5' STO

≪ ?BSD ≫ TEST5
≪ ?MS ≫ TEST5

Output:
2: { 12345 1406932606 654583775 1449466924 229283573 }
1: { 38 7719 21238 2437 8855 }


## Ruby

You can create multiple instances of LCG::Berkeley or LCG::Microsoft. Each instance privately keeps the original seed in @seed, and the current state in @r. Each class resembles the core Random class, but with fewer features. The .new method takes a seed. The #rand method returns the next random number. The #seed method returns the original seed.

module LCG
module Common
# The original seed of this generator.

# Creates a linear congruential generator with the given _seed_.
def initialize(seed)
@seed = @r = seed
end
end

# LCG::Berkeley generates 31-bit integers using the same formula
# as BSD rand().
class Berkeley
include Common
def rand
@r = (1103515245 * @r + 12345) & 0x7fff_ffff
end
end

# LCG::Microsoft generates 15-bit integers using the same formula
# as rand() from the Microsoft C Runtime.
class Microsoft
include Common
def rand
@r = (214013 * @r + 2531011) & 0x7fff_ffff
@r >> 16
end
end
end


The next example sets the seed to 1, and prints the first 5 random numbers.

lcg = LCG::Berkeley.new(1)
p (1..5).map {lcg.rand}
# prints [1103527590, 377401575, 662824084, 1147902781, 2035015474]

lcg = LCG::Microsoft.new(1)
p (1..5).map {lcg.rand}
# prints [41, 18467, 6334, 26500, 19169]


## Run BASIC

global bsd
global ms
print "Num  ___Bsd___";chr$(9);"__Ms_" for i = 1 to 10 print using("##",i);using("############",bsdRnd());chr$(9);using("#####",msRnd())
next i

function bsdRnd()
bsdRnd = (1103515245 * bsd + 12345) mod (2 ^ 31)
bsd = bsdRnd
end function

function msRnd()
ms = (214013 * ms + 2531011) mod (2 ^ 31)
msRnd = int(ms / 2 ^ 16)
end function
Num  ___Bsd___	__Ms_
1       12345	   38
2  1406932606	 7719
3   654583775	21238
4  1449466924	 2437
5   229283573	 8855
6  1109335178	11797
7  1051550459	 8365
8  1293799192	32285
9   794471793	10450
10   551188310	30612

## Rust

extern crate rand;

pub use rand::{Rng, SeedableRng};

pub struct BsdLcg {
state: u32,
}

impl Rng for BsdLcg {
// Because the output is in the range [0, 2147483647], this should technically be next_u16
// (the largest integer size which is fully covered, as rand::Rng assumes).  The rand
// crate does not provide it however.  If serious usage is required, implementing this
// function as a concatenation of two next_u16s (elsewhere defined) should work.
fn next_u32(&mut self) -> u32 {
self.state %= 1 << 31;
self.state
}
}

impl SeedableRng<u32> for BsdLcg {
fn from_seed(seed: u32) -> Self {
Self { state: seed }
}
fn reseed(&mut self, seed: u32) {
self.state = seed;
}
}

pub struct MsLcg {
state: u32,
}

impl Rng for MsLcg {
// Similarly, this outputs in the range [0, 32767] and should output a u8.  Concatenate
// four next_u8s for serious usage.
fn next_u32(&mut self) -> u32 {
self.state %= 1 << 31;
self.state >> 16 // rand_n = state_n / 2^16
}
}

impl SeedableRng<u32> for MsLcg {
fn from_seed(seed: u32) -> Self {
Self { state: seed }
}
fn reseed(&mut self, seed: u32) {
self.state = seed;
}
}

fn main() {
println!("~~~ BSD ~~~");
let mut bsd = BsdLcg::from_seed(0);
for _ in 0..10 {
println!("{}", bsd.next_u32());
}

println!("~~~ MS ~~~");
let mut ms = MsLcg::from_seed(0);
for _ in 0..10 {
println!("{}", ms.next_u32());
}

// Because we have implemented the rand::Rng trait, we can generate a variety of other types.
println!("~~~ Others ~~~");
println!("{:?}", ms.gen::<[u32; 5]>());
println!("{}", ms.gen::<bool>());
println!("{}", ms.gen_ascii_chars().take(15).collect::<String>());
}


## Scala

object LinearCongruentialGenerator {
def bsdRandom(rseed:Int):Iterator[Int]=new Iterator[Int]{
var seed=rseed
override def hasNext:Boolean=true
override def next:Int={seed=(seed * 1103515245 + 12345) & Int.MaxValue; seed}
}

def msRandom(rseed:Int):Iterator[Int]=new Iterator[Int]{
var seed=rseed
override def hasNext:Boolean=true
override def next:Int={seed=(seed * 214013 + 2531011) & Int.MaxValue; seed >> 16}
}

def toString(it:Iterator[Int], n:Int=20)=it take n mkString ", "

def main(args:Array[String]){
println("-- seed 0 --")
println("BSD: "+ toString(bsdRandom(0)))
println("MS : "+ toString(msRandom(0)))

println("-- seed 1 --")
println("BSD: "+ toString(bsdRandom(1)))
println("MS : "+ toString( msRandom(1)))
}
}

Output:
-- seed 0 --
BSD: 12345, 1406932606, 654583775, 1449466924, 229283573, 1109335178, 1051550459, 1293799192,
794471793, 551188310, 803550167, 1772930244, 370913197, 639546082, 1381971571, 1695770928,
2121308585, 1719212846, 996984527, 1157490780

MS : 38, 7719, 21238, 2437, 8855, 11797, 8365, 32285, 10450, 30612, 5853, 28100, 1142, 281, 20537,
15921, 8945, 26285, 2997, 14680

-- seed 1 --
BSD: 1103527590, 377401575, 662824084, 1147902781, 2035015474, 368800899, 1508029952, 486256185,
1062517886, 267834847, 180171308, 836760821, 595337866, 790425851, 2111915288, 1149758321,
1644289366, 1388290519, 1647418052, 1675546029

MS : 41, 18467, 6334, 26500, 19169, 15724, 11478, 29358, 26962, 24464, 5705, 28145, 23281, 16827,
9961, 491, 2995, 11942, 4827, 5436

## Scheme

For R7RS Scheme.

(import (scheme base)
(scheme write))

(define ((bsd-rand state))
(set! state (remainder (+ (* 1103515245 state) 12345) 2147483648))
state)

(define ((msvcrt-rand state))
(set! state (remainder (+ (* 214013 state) 2531011) 2147483648))
(quotient state 65536))

; auxiliary function to get a list of 'n random numbers from generator 'r
(define (rand-list r n)
(if (zero? n) '() (cons (r) (rand-list r (- n 1)))))

(display (rand-list (bsd-rand 0) 10))
; (12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310)

(newline)

(display (rand-list (msvcrt-rand 0) 10))
; (38 7719 21238 2437 8855 11797 8365 32285 10450 30612)


## Seed7

Seed7 provides also a random number generator. The random function is overloaded for many types. E.g.: The library integer.s7i defines rand(lower, upper). The parameters specifiy the lower and upper bound of the desired random value. The library array.s7i defines rand(arr). This function selects a random element from an array.

$include "seed7_05.s7i"; include "bigint.s7i"; var bigInteger: bsdSeed is 0_; var bigInteger: msSeed is 0_; const func integer: bsdRand is func result var integer: bsdRand is 0; begin bsdSeed := (1103515245_ * bsdSeed + 12345_) mod 2147483648_; bsdRand := ord(bsdSeed); end func; const func integer: msRand is func result var integer: msRand is 0; begin msSeed := (214013_ * msSeed + 2531011_) mod 2147483648_; msRand := ord(msSeed) mdiv 65536; end func; const proc: main is func local var integer: i is 0; begin writeln(" BSD MS"); for i range 1 to 10 do writeln(bsdRand lpad 12 <& msRand lpad 12); end for; end func; Output:  BSD MS 12345 38 1406932606 7719 654583775 21238 1449466924 2437 229283573 8855 1109335178 11797 1051550459 8365 1293799192 32285 794471793 10450 551188310 30612  ## SequenceL Uses the Random library provided by SequenceL to create new Random Number Generators import <Utilities/Random.sl>; main(args(2)) := let bsdRandomGenerator := newRandomGenerator(0, 0, 2147483647, bsdNext); msRandomGenerator := newRandomGenerator(0, 0, 32767, msNext); // Create a random sequence with each one of the generators numbers := getRandomSequence([bsdRandomGenerator, msRandomGenerator], 10).Value; in "BSD Values: " ++ toString(numbers[1]) ++ "\nMS Values: " ++ toString(numbers[2]); bsdNext(RG) := let newSeed := ((1103515245 -> int64 * RG.Seed + 12345) mod 2147483648) -> int32; in (Value : newSeed, Generator : (Seed : newSeed, RandomMin : RG.RandomMin, RandomMax : RG.RandomMax, NextFunction : RG.NextFunction)); msNext(RG) := let newSeed := ((214013 -> int64 * RG.Seed + 2531011) mod 2147483648) -> int32; in (Value : newSeed / 65536, Generator : (Seed : newSeed, RandomMin : RG.RandomMin, RandomMax : RG.RandomMax, NextFunction : RG.NextFunction)); Output BSD Values: [12345,1406932606,654583775,1449466924,229283573,1109335178,1051550459,1293799192,794471793,551188310] MS Values: [38,7719,21238,2437,8855,11797,8365,32285,10450,30612]  ## Sidef Translation of: Ruby module LCG { # Creates a linear congruential generator and remembers the initial seed. class Common(r) { has seed = r } # LCG::Berkeley generates 31-bit integers using the same formula # as BSD rand(). class Berkeley < Common { method rand { self.r = ((1103515245 * self.r + 12345) & 0x7fff_ffff); } } # LCG::Microsoft generates 15-bit integers using the same formula # as rand() from the Microsoft C Runtime. class Microsoft < Common { method rand { self.r = ((214013 * self.r + 2531011) & 0x7fff_ffff); self.r >> 16; } } } var lcg1 = LCG::Berkeley(1) say 5.of { lcg1.rand } var lcg2 = LCG::Microsoft(1) say 5.of { lcg2.rand }  Output: [1103527590, 377401575, 662824084, 1147902781, 2035015474] [41, 18467, 6334, 26500, 19169]  ## Sparkling var states = { "BSD": 0, "MS": 0 }; function BSD_seed(n) { states.BSD = n; } function BSD_rand() { return states.BSD = (1103515245 * states.BSD + 12345) % (1 << 31); } function Microsoft_seed(n) { states.MS = n; } function Microsoft_rand() { return (states.MS = (214013 * states.MS + 2531011) % (1 << 31)) % (1 << 15); } Output seen after seeding both generators with 0: spn:8> Microsoft_seed(0); spn:9> Microsoft_rand() = 7875 spn:10> Microsoft_rand() = 3706 spn:11> Microsoft_rand() = 23381 spn:12> Microsoft_rand() = 8388 spn:13> Microsoft_rand() = 19575 spn:14> BSD_seed(0); spn:15> BSD_rand() = 12345 spn:16> BSD_rand() = 1406932606 spn:17> BSD_rand() = 654583775 spn:18> BSD_rand() = 1449466924 spn:19> BSD_rand() = 229283573 ## Standard ML local open Word32 in fun bsdLcg (seed : int) : int = toInt (andb (0w1103515245 * fromInt seed + 0w12345, 0wx7fffffff)) fun mscLcg (seed : word) : int * word = let val state = andb (0w214013 * seed + 0w2531011, 0wx7fffffff) in (toInt (>> (state, 0w16)), state) end end  Test code: fun test1 rand = (print (" " ^ Int.toString rand); rand) fun test2 (rand, state) = (print (" " ^ Int.toString rand); state) fun doTimes (_, 0, state) = () | doTimes (f, n, state) = doTimes (f, n - 1, f state) val () = print "BSD:\n" val () = doTimes (test1 o bsdLcg, 7, 0) val () = print "\nMSC:\n" val () = doTimes (test2 o mscLcg, 7, 0w0) val () = print "\n"  Output: BSD: 12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 MSC: 38 7719 21238 2437 8855 11797 8365 ## Stata mata function rand_bsd(u) { m = 65536 u1 = floor(u/m) u2 = mod(u,m) a1 = 16838 a2 = 20077 b = 12345 u = mod((a1*u2+a2*u1)*m+a2*u2+b,2147483648) return(u) } function rand_ms(u) { u = mod(214013*u+2531011,2147483648) return(floor(u/65536)) } function rand_seq(f,seed,n) { a = J(n,1,.) for (i=1; i<=n; i++) a[i] = (*f)(seed) return(a) } rand_seq(&rand_bsd(),1,10) rand_seq(&rand_ms(),0,10)  Output: compare with OEIS A096553 and A096558.  1 +--------------+ 1 | 1103527590 | 2 | 377401575 | 3 | 662824084 | 4 | 1147902781 | 5 | 2035015474 | 6 | 368800899 | 7 | 1508029952 | 8 | 486256185 | 9 | 1062517886 | 10 | 267834847 | +--------------+ 1 +---------+ 1 | 38 | 2 | 7719 | 3 | 21238 | 4 | 2437 | 5 | 8855 | 6 | 11797 | 7 | 8365 | 8 | 32285 | 9 | 10450 | 10 | 30612 | +---------+ ## Swift import Cocoa class LinearCongruntialGenerator { var state = 0 //seed of 0 by default let a, c, m, shift: Int //we will use microsoft random by default init() { self.a = 214013 self.c = 2531011 self.m = Int(pow(2.0, 31.0)) //2^31 or 2147483648 self.shift = 16 } init(a: Int, c: Int, m: Int, shift: Int) { self.a = a self.c = c self.m = m //2^31 or 2147483648 self.shift = shift } func seed(seed: Int) -> Void { state = seed; } func random() -> Int { state = (a * state + c) % m return state >> shift } } let microsoftLinearCongruntialGenerator = LinearCongruntialGenerator() let BSDLinearCongruntialGenerator = LinearCongruntialGenerator(a: 1103515245, c: 12345, m: 2147483648, shift: 0) print("Microsft Rand:") for(var i = 0; i < 10; i++) { print(microsoftLinearCongruntialGenerator.random()) } print("") //new line for readability print("BSD Rand:") for(var i = 0; i < 10; i++) { print(BSDLinearCongruntialGenerator.random()) }  Output: Microsft Rand: 38 7719 21238 2437 8855 11797 8365 32285 10450 30612 BSD Rand: 12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310 ## Tcl Using an object-oriented solution, inspired by (but not a translation of) the Ruby solution above. package require Tcl 8.6 # General form of a linear-congruential RNG oo::class create LCRNG { variable seed A B C D constructor {init a b c d} { if {$init < 1} {set init [clock clicks]}
variable seed $init A$a B $b C$c D $d } method rand {} { set seed [expr {($A * $seed +$B) % $C}] return [expr {$seed / $D}] } method srand x { set seed$x
}
}
# Subclass to introduce constants
oo::class create BSDRNG {
superclass LCRNG
constructor {{initialSeed -1}} {
next $initialSeed 1103515245 12345 [expr {2**31}] 1 } } oo::class create MSRNG { superclass LCRNG constructor {{initialSeed -1}} { next$initialSeed 214013 2531011 [expr {2**31}] [expr {2**16}]
}
}


Demo code:

proc sample rng {foreach - {1 2 3 4 5} {lappend r [$rng rand]}; join$r ", "}
puts BSD:\t$[sample [BSDRNG new 1]]$
puts MS:\t$[sample [MSRNG new 1]]$


Output:

BSD:	[1103527590, 377401575, 662824084, 1147902781, 2035015474]
MS:	[41, 18467, 6334, 26500, 19169]


## uBasic/4tH

uBasic is an integer BASIC without any bitwise operations. That's why a trick is used when it enters the negative domain. Unfortunately, it is not portable and must be adjusted for different integer widths. This 32-bit version produces the proper result, though.

w = 32                                 ' Change for different integer size
b = 0                                  ' Initial BSD seed
m = 0                                  ' Initial MS seed

Print "BSD"                            ' Get the first 10 numbers from BSD
For i = 1 To 10
GoSub _randBSD
Print Pop()
Next i

Print

Print "Microsoft"                      ' Get the first 10 numbers from MS
For i = 1 To 10
GoSub _randMS
Print Pop()
Next i

End

_randBSD                               ' ( n1 -- n2)
Push (1103515245 * b + 12345)      ' Compensate for the sign bit
If Tos() < 0 Then Push (Pop() - (2 ^ (w-1)))
b = Pop() % (2 ^ 31)               ' Now we got a number less than 2^31
Push b                             ' So we can complete the operation
Return

_randMS                                ' ( n1 -- n2)
Push (214013 * m + 2531011)        ' Compensate for the sign bit
If Tos() < 0 Then Push (Pop() - (2 ^ (w-1)))
m =  Pop() % (2 ^ 31)              ' Now we got a number less than 2^31
Push m / (2 ^ 16)                  ' So we can complete the operation
Return

Output:
BSD
12345
1406932606
654583775
1449466924
229283573
1109335178
1051550459
1293799192
794471793
551188310

Microsoft
38
7719
21238
2437
8855
11797
8365
32285
10450
30612

0 OK, 0:908


## UNIX Shell

#! /bin/bash

function BSD() {
SEED=$(((1103515245 *$SEED + 12345) % 2**31))
echo "  $SEED" } function MS() { SEED=$(((214013 * $SEED + 2531011) % 2**31)) echo "$(($SEED / 2**16))" } function output() { SEED=0 echo "$1"

for i in {1..10}; do
eval "$1" done echo "" } output BSD output MS  Output: BSD 12345 1406932606 654583775 1449466924 229283573 1109335178 1051550459 1293799192 794471793 551188310 MS 38 7719 21238 2437 8855 11797 8365 32285 10450 30612  ## VBA Public stateBSD As Variant Public stateMS As Variant Private Function bsd() As Long Dim temp As Variant temp = CDec(1103515245 * stateBSD + 12345) temp2 = temp / 2 ^ 31 temp3 = CDec(WorksheetFunction.Floor_Precise(temp2)) stateBSD = temp - (2 ^ 31) * temp3 bsd = stateBSD End Function Private Function ms() As Integer Dim temp As Variant temp = CDec(214013 * stateMS + 2531011) temp2 = temp / 2 ^ 31 temp3 = CDec(WorksheetFunction.Floor_Precise(temp2)) stateMS = temp - (2 ^ 31) * temp3 ms = stateMS \ 2 ^ 16 End Function Public Sub main() stateBSD = CDec(0) stateMS = CDec(0) Debug.Print " BSD", " MS" For i = 1 To 10 Debug.Print Format(bsd, "@@@@@@@@@@"), Format(ms, "@@@@@") Next i End Sub Output:  BSD MS 12345 38 1406932606 7719 654583775 21238 1449466924 2437 229283573 8855 1109335178 11797 1051550459 8365 1293799192 32285 794471793 10450 551188310 30612 ## Wren Translation of: Go Library: Wren-big Library: Wren-fmt Some of the intermediate calculations here require integers >= 2^53 so we need to use BigInt. import "./big" for BigInt import "./fmt" for Fmt // basic linear congruential generator var lcg = Fn.new { |a, c, m, seed| var r = BigInt.new(seed) return Fn.new { r = (r*a + c) % m return r } } // Microsoft generator has extra division step var msg = Fn.new { |seed| var g = lcg.call(214013, 2531011, 1<<31, seed) return Fn.new { g.call()/(1 << 16) } } var example = Fn.new { |seed| System.print("\nWith seed = %(seed):") var bsd = lcg.call(1103515245, 12345, 1<<31, seed) var msf = msg.call(seed) System.print(" BSD MSF") for (i in 0..4) { Fmt.print("$10i    5i", bsd.call(), msf.call()) } } example.call(0) example.call(1)  Output: With seed = 0: BSD MSF 12345 38 1406932606 7719 654583775 21238 1449466924 2437 229283573 8855 With seed = 1: BSD MSF 1103527590 41 377401575 18467 662824084 6334 1147902781 26500 2035015474 19169  ## X86 Assembly These programs are based off of the implementations described in this article: "https://software.intel.com/en-us/articles/fast-random-number-generator-on-the-intel-pentiumr-4-processor", using the Microsoft equation. First example using integer instructions. ;x86-64 assembly code for Microsoft Windows ;Tested in windows 7 Enterprise Service Pack 1 64 bit ;With the AMD FX(tm)-6300 processor ;Assembled with NASM version 2.11.06 ;Linked to C library with gcc version 4.9.2 (x86_64-win32-seh-rev1, Built by MinGW-W64 project) ;Assembled and linked with the following commands: ;nasm -f win64 <filename>.asm -o <filename>.obj ;gcc <filename>.obj -o <filename> ;Takes number of iterations to run RNG loop as command line parameter. extern printf,puts,atoi,exit,time,malloc section .data align 64 errmsg_argnumber: db "There should be no more than one argument.",0 align 64 errmsg_noarg: db "Number of iterations was not specified.",0 align 64 errmsg_zeroiterations: db "Zero iterations of RNG loop specified.",0 align 64 errmsg_timefail: db "Unable to retrieve calender time.",0 align 64 errmsg_mallocfail: db "Unable to allocate memory for array of random numbers.",0 align 64 fmt_random: db "The %u number generated is %d",0xa,0xd,0 section .bss section .text global main main: ;check for argument cmp rcx,1 jle err_noarg ;ensure that only one argument was entered cmp rcx,2 jg err_argnumber ;get number of times to iterate get_random mov rcx,[rdx + 8] call atoi ;ensure that number of iterations is greater than 0 cmp rax,0 jle err_zeroiterations mov rcx,rax ;calculate space needed for an array containing the random numbers shl rcx,2 ;move size of array into r14 mov r14,rcx ;reserve memory for array of random numbers with malloc call malloc cmp rax,0 jz err_mallocfail ;pointer to array in r15 mov r15,rax ;seed the RNG using time() xor rcx,rcx call time ;ensure that time returns valid output cmp rax,-1 jz err_timefail ;calculate address of end of array in r14 add r14,r15 ;pointer to array of random numbers in r15 ;address of end of array in r14 ;current address in array in rdi ;multiplier in rbx ;seed in rax ;current random number in rcx ;prepare random number generator mov rdi,r15 mov rbx,214013 get_random: ;multiply by 214013 and add 2561011 to get next state mul ebx add eax,2531011 ;shr by 16 and AND with 0x7FFF to get current random number mov ecx,eax shr ecx,16 and ecx,0x7fff ;store random number in array mov [rdi],ecx add rdi,4 cmp rdi,r14 jl get_random ;pointer to array of random numbers in r15 ;address of end of array in r14 ;current address in array in rdi ;array index in rsi xor rsi,rsi mov rdi,r15 print_random: mov rcx,fmt_random mov rdx,rsi mov r8d,[rdi] call printf add rsi,1 add rdi,4 cmp rdi,r14 jl print_random xor rcx,rcx call exit ;;;;;;;;;;ERROR MESSAGES;;;;;;;;;;;;;;;; err_argnumber: mov rcx,errmsg_argnumber call puts jmp exit_one err_noarg: mov rcx,errmsg_noarg call puts jmp exit_one err_zeroiterations: mov rcx,errmsg_zeroiterations call puts jmp exit_one err_timefail: mov rcx,errmsg_timefail call puts jmp exit_one err_mallocfail: mov rcx,errmsg_mallocfail call puts exit_one: mov rcx,1 call exit  Second example using AVX instructions.  This example is incorrect. Please fix the code and remove this message.Details: It will not produce output identical to that of the Microsoft rand() function. ;x86-64 assembly code for Microsoft Windows ;Tested in windows 7 Enterprise Service Pack 1 64 bit ;With the AMD FX(tm)-6300 processor ;Assembled with NASM version 2.11.06 ;Linked to C library with gcc version 4.9.2 (x86_64-win32-seh-rev1, Built by MinGW-W64 project) ;Assembled and linked with the following commands: ;nasm -f win64 <filename>.asm -o <filename>.obj ;gcc <filename>.obj -o <filename> ;Takes number of iterations to run RNG loop as command line parameter. extern printf,puts,atoi,exit,time,_aligned_malloc section .data align 64 errmsg_argnumber: db "There should be no more than one argument.",0 align 64 errmsg_noarg: db "Number of iterations was not specified.",0 align 64 errmsg_zeroiterations: db "Zero iterations of RNG loop specified.",0 align 64 errmsg_timefail: db "Unable to retrieve calender time.",0 align 64 errmsg_mallocfail: db "Unable to allocate memory for array of random numbers.",0 align 64 fmt_random: db "The %u number generated is %d",0xa,0xd,0 align 16 multiplier: dd 214013,17405,214013,69069 align 16 addend: dd 2531011, 10395331, 13737667, 1 align 16 mask: dd 0xffffffff,0,0xffffffff,0 align 16 masklo: dd 0x7fff,0x7fff,0x7fff,0x7fff section .bss section .text global main main: ;check for argument cmp rcx,1 jle err_noarg ;ensure that only one argument was entered cmp rcx,2 jg err_argnumber ;get number of times to iterate get_random mov rcx,[rdx + 8] call atoi ;ensure that number of iterations is greater than 0 cmp rax,0 jle err_zeroiterations mov rcx,rax ;calculate space needed for an array containing the random numbers shl rcx,4 ;move size of array into r14 mov r14,rcx ;16 byte alignment boundary mov rdx,16 ;reserve memory aligned to 16 byte boundary for array with _aligned_malloc call _aligned_malloc cmp rax,0 jz err_mallocfail ;pointer to array in r15 mov r15,rax ;seed the RNG using time() xor rcx,rcx call time ;ensure that time returns valid output cmp rax,-1 jz err_timefail ;pointer to array of random numbers in r15 ;address of end of array at in r14 ;states stored in xmm0 ;calculate address of end of array in r14 add r14,r15 ;load seed,seed+1,seed,seed+1 into xmm0 lea rbx,[rax - 1] shl rax,32 or rax,rbx movq xmm0,rax vpslldq xmm1,xmm0,8 vpor xmm0,xmm0,xmm1 ;pointer to array of random numbers in r15 ;address of end of array in r14 ;current address in array in rdi ;current states in xmm0 ;multiplier in xmm1 ;addened in xmm2 ;mask in xmm3 ;masklo in xmm4 ;split seed in xmm5 ;current set of random numbers in xmm6 ;prepare random number generator mov rdi,r15 vmovdqa xmm1,[multiplier] vmovdqa xmm2,[addend] vmovdqa xmm3,[mask] vmovdqa xmm4,[masklo] get_random: ;arrange order of current states to 2,3,0,1 and store in split seed vpshufd xmm5,xmm0,10110001b ;multiply current states by multiplier vpmulld xmm0,xmm0,xmm1 ;set order of multiplier to 2,3,0,1 vpshufd xmm1,xmm1,10110001b ;multiply split seed by multiplier vpmulld xmm5,xmm5,xmm1 ;and current states with mask vpand xmm0,xmm0,xmm3 ;and current split seed with mask vpand xmm5,xmm5,xmm3 ;set order of split seed to 2,3,0,1 vpshufd xmm5,xmm5,10110001b ;or current states with split seed vpor xmm0,xmm0,xmm5 ;add adder to current states vpaddd xmm0,xmm0,xmm2 ;shift vector right by two bytes vpsrldq xmm6,xmm0,2 ;and each state with 0x7fff vpand xmm6,xmm6,xmm4 vmovdqa [rdi],xmm6 add rdi,16 cmp rdi,r14 jl get_random ;pointer to array of random numbers in r15 ;address of end of array in r14 ;current address in array in rdi ;array index in rsi xor rsi,rsi mov rdi,r15 print_random: mov rcx,fmt_random mov rdx,rsi mov r8d,[rdi] call printf add rsi,1 add rdi,4 cmp rdi,r14 jl print_random xor rcx,rcx call exit ;;;;;;;;;;ERROR MESSAGES;;;;;;;;;;;;;;;; err_argnumber: mov rcx,errmsg_argnumber call puts jmp exit_one err_noarg: mov rcx,errmsg_noarg call puts jmp exit_one err_zeroiterations: mov rcx,errmsg_zeroiterations call puts jmp exit_one err_timefail: mov rcx,errmsg_timefail call puts jmp exit_one err_mallocfail: mov rcx,errmsg_mallocfail call puts exit_one: mov rcx,1 call exit  Sample: Integer instruction example: F:\>lcgint.exe 20 The 0 number generated is 20272 The 1 number generated is 4467 The 2 number generated is 8618 The 3 number generated is 1587 The 4 number generated is 2687 The 5 number generated is 21398 The 6 number generated is 29522 The 7 number generated is 27724 The 8 number generated is 23875 The 9 number generated is 2399 The 10 number generated is 4086 The 11 number generated is 923 The 12 number generated is 23002 The 13 number generated is 11586 The 14 number generated is 13200 The 15 number generated is 22090 The 16 number generated is 26528 The 17 number generated is 14271 The 18 number generated is 10476 The 19 number generated is 9981 F:\> AVX instruction example: F:\>lcgavx.exe 5 The 0 number generated is 20370 The 1 number generated is 45 The 2 number generated is 20541 The 3 number generated is 15699 The 4 number generated is 23637 The 5 number generated is 30131 The 6 number generated is 26151 The 7 number generated is 27319 The 8 number generated is 26933 The 9 number generated is 28417 The 10 number generated is 16647 The 11 number generated is 14840 The 12 number generated is 29228 The 13 number generated is 16968 The 14 number generated is 1027 The 15 number generated is 12099 The 16 number generated is 17170 The 17 number generated is 23893 The 18 number generated is 18556 The 19 number generated is 16434 F:\> ## XPL0 It's not easy just by looking at the numbers generated if they are sufficiently random. You might notice that the BSD numbers alternate odd and even, which is pretty bad. A simple but effective test is to simulate falling snowflakes. include c:\cxpl\codes; int R; func BSD; [R:= (1103515245*R + 12345) &7FFF_FFFF;
return R;
]; \BSD

func MSFT;
[R:= (214013*R + 2531011) & \$7FFF_FFFF;
return R>>16;
]; \MSFT

int N;
[SetVid(4);             \320x200x2 graphics
R:= 0;                  \initialize seed
for N:= 0 to 5000 do
Point(rem(BSD/180), rem(BSD/180), 3);
N:= ChIn(1);            \wait for keystoke

SetVid(4);              \320x200x2 graphics
R:= 0;                  \initialize seed
for N:= 0 to 5000 do
Point(rem(MSFT/180), rem(MSFT/180), 3);
N:= ChIn(1);            \wait for keystoke
SetVid(3);              \restore normal text mode
]

## zkl

var [private] seed = 0;
fcn srand(s){ seed = s }

const TWO31=(1).shiftLeft(31);

//#define BSD_RAND 1

#ifdef BSD_RAND
const A=1103515245, C=12345;
fcn rand{ seed = (seed * A + C) % TWO31 }
#else  // MS rand
const A=214013, C=2531011, TWO16=(1).shiftLeft(16);
fcn rand{ (seed = (seed * A + C) % TWO31) / TWO16 }
#endif
srand(0);
println(rand(),",",rand(),",",rand());
Output:
MS:  38,7719,21238
BSD: 12345,1406932606,654583775
`