Loops/Nested: Difference between revisions
| Line 693: | Line 693: | ||
do i = 1 to hbound(x,1); |
do i = 1 to hbound(x,1); |
||
do j = 1 to hbound(x,2); |
do j = 1 to hbound(x,2); |
||
put (x(i,j)); |
|||
if x(i,j) = 20 then leave loops; |
if x(i,j) = 20 then leave loops; |
||
end; |
end; |
||
Revision as of 03:08, 16 August 2010
You are encouraged to solve this task according to the task description, using any language you may know.
Show a nested loop which searches two-dimensional array filled with random number uniformly distributed on [1..20]. The loops iterate rows and columns of the array printing the iterated elements of, until the value 20 is met. Specifically, this task also shows how to break out of nested loops.
Ada
<lang ada>with Ada.Text_IO; use Ada.Text_IO; with Ada.Numerics.Discrete_Random;
procedure Test_Loop_Nested is
type Value_Type is range 1..20;
package Random_Values is new Ada.Numerics.Discrete_Random (Value_Type);
use Random_Values;
Dice : Generator;
A : array (1..10, 1..10) of Value_Type :=
(others => (others => Random (Dice)));
begin
Outer :
for I in A'Range (1) loop
for J in A'Range (2) loop
Put (Value_Type'Image (A (I, J)));
exit Outer when A (I, J) = 20;
end loop;
New_Line;
end loop Outer;
end Test_Loop_Nested;</lang> Sample output:
16 3 1 17 13 5 4 2 19 1 5 5 17 15 17 2 5 5 17 13 16 10 10 20
ALGOL 68
- note: This specimen retains the original C coding style.
<lang algol68>main: (
[10][10]INT a; INT i, j;
FOR i FROM LWB a TO UPB a DO
FOR j FROM LWB a[i] TO UPB a[i] DO
a[i][j] := ENTIER (random * 20 + 1)
OD
OD ;
FOR i FROM LWB a TO UPB a DO
FOR j FROM LWB a[i] TO UPB a[i] DO
print(whole(a[i][j], -3));
IF a[i][j] = 20 THEN
GO TO xkcd com 292 # http://xkcd.com/292/ #
FI
OD;
print(new line)
OD;
xkcd com 292:
print(new line)
)</lang> Sample output:
8 14 17 6 18 1 1 7 9 6 8 9 1 15 3 1 10 19 6 7 12 20
AutoHotkey
<lang AutoHotkey>Loop, 10 {
i := A_Index
Loop, 10
{
j := A_Index
Random, a%i%%j%, 1, 20
}
}
Loop, 10 {
i := A_Index
Loop, 10
{
j := A_Index
If (a%i%%j% == 20)
Goto finish
}
}
finish:
MsgBox % "a[" . i . "][" . j . "]" is 20
Return</lang>
BASIC
<lang qbasic>DIM a(1 TO 10, 1 TO 10) AS INTEGER CLS FOR row = 1 TO 10
FOR col = 1 TO 10
a(row, col) = INT(RND * 20) + 1
NEXT col
NEXT row
FOR row = LBOUND(a, 1) TO UBOUND(a, 1)
FOR col = LBOUND(a, 2) TO UBOUND(a, 2)
PRINT a(row, col)
IF a(row, col) = 20 THEN END
NEXT col
NEXT row</lang>
C
Using goto (note: gotos are considered harmful): <lang c>#include <stdlib.h>
- include <time.h>
- include <stdio.h>
int main() {
int a[10][10], i, j;
srand(time(NULL));
for (i = 0; i < 10; i++)
for (j = 0; j < 10; j++)
a[i][j] = rand() % 20 + 1;
for (i = 0; i < 10; i++) {
for (j = 0; j < 10; j++) {
printf(" %d", a[i][j]);
if (a[i][j] == 20)
goto Done;
}
printf("\n");
}
Done:
printf("\n");
return 0;
}</lang>
C#
Uses goto as C# has no way to break from multiple loops
<lang csharp>using System;
class Program {
static void Main(string[] args) {
int[,] a = new int[10, 10];
Random r = new Random();
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
a[i, j] = r.Next(0, 20) + 1;
}
}
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
Console.Write(" {0}", a[i, j]);
if (a[i, j] == 20) {
goto Done;
}
}
Console.WriteLine();
}
Done:
Console.WriteLine();
}
}</lang>
Clojure
We explicitly return a status flag from the inner loop:
<lang clojure>(ns nested
(:import (java.util Random)))
(let [generator (Random.)]
(defn random-int [max] "Random integer in [1, max]." (inc (.nextInt generator max))))
(defn create-matrix [width height]
(letfn [(create-row [] (take width (repeatedly #(random-int 20))))] (take height (repeatedly create-row))))
(defn print-matrix [matrix]
(loop [[row & rs] matrix]
(condp = (loop [[x & xs] row]
(println x)
(if (= x 20)
:stop
(if xs
(recur xs)
:continue)))
:continue (when rs (recur rs))
:stop nil)))
(print-matrix (create-matrix 10 10))</lang>
Common Lisp
<lang lisp>(let ((a (make-array '(10 10))))
(dotimes (i 10)
(dotimes (j 10)
(setf (aref a i j) (1+ (random 20)))))
(block outer
(dotimes (i 10)
(dotimes (j 10)
(princ " ")
(princ (aref a i j))
(if (= 20 (aref a i j))
(return-from outer)))
(terpri))
(terpri)))</lang>
D
<lang d>import std.stdio, std.random;
void main() {
int[10][10] m;
foreach (ref row; m)
foreach (ref item; row)
item = rand % 20 + 1;
outer:
foreach (row; m)
foreach (item; row) {
writef(item, ' ');
if (item == 20)
break outer;
}
writefln;
}</lang>
E
<lang e>def array := accum [] for i in 1..5 { _.with(accum [] for i in 1..5 { _.with(entropy.nextInt(20) + 1) }) }
escape done {
for row in array {
for x in row {
print(`$x$\t`)
if (x == 20) {
done()
}
}
println()
}
} println("done.")</lang>
Forth
<lang forth>include random.fs
10 constant X 10 constant Y
- ,randoms ( range n -- ) 0 do dup random 1+ , loop drop ;
create 2darray 20 X Y * ,randoms
- main
Y 0 do
cr
X 0 do
j X * i + cells 2darray + @
dup .
20 = if unloop unloop exit then
loop
loop ;</lang>
Fortran
<lang fortran>program Example
implicit none
real :: ra(5,10) integer :: ia(5,10) integer :: i, j
call random_number(ra) ia = int(ra * 20.0) + 1
outer: do i = 1, size(ia, 1)
do j = 1, size(ia, 2)
write(*, "(i3)", advance="no") ia(i,j)
if (ia(i,j) == 20) exit outer
end do
write(*,*)
end do outer
end program Example</lang> Sample output:
14 2 1 11 8 1 14 11 3 15 7 15 16 6 7 17 3 20
Go
<lang go>package main
import (
"fmt" "rand" "time"
)
func main() {
rand.Seed(time.Nanoseconds())
values := make([][]int,10)
for i := range values {
values[i] = make([]int,10)
for j := range values[i] {
values[i][j] = rand.Intn(20) + 1
}
}
outerLoop:
for i, row := range values {
fmt.Printf("%3d)", i)
for _, value := range row {
fmt.Printf(" %3d", value)
if value == 20 { break outerLoop }
}
fmt.Printf("\n")
}
fmt.Printf("\n")
}</lang>
Haskell
<lang haskell>import Data.List
breakIncl p = uncurry ((. take 1). (++)). break p
taskLLB k = map (breakIncl (==k)). breakIncl (k`elem`)</lang> Example: <lang haskell>mij :: Int mij = takeWhile(not.null). unfoldr (Just. splitAt 5) $
[2, 6, 17, 5, 14, 1, 9, 11, 18, 10, 13, 20, 8, 7, 4, 16, 15, 19, 3, 12]
- Main> mapM_ (mapM_ print) $ taskLLB 20 mij
2 6 17 5 14 1 9 11 18 10 13 20</lang>
HicEst
<lang hicest>REAL :: n=20, array(n,n)
array = NINT( RAN(10,10) )
DO row = 1, n
DO col = 1, n WRITE(Name) row, col, array(row,col) IF( array(row, col) == 20 ) GOTO 99 ENDDO
ENDDO
99 END</lang>
Icon and Unicon
Icon and Unicon use 'break' to exit loops and execute an expression argument. To exit nested loops 'break' is repeated as the expression.
Icon
<lang Icon>procedure main()
every !(!(L := list(10)) := list(10)) := ?20 # setup a 2d array of random numbers up to 20
every i := 1 to *L do # using nested loops
every j := 1 to *L[i] do
if L[i,j] = 20 then
break break write("L[",i,",",j,"]=20")
end</lang>
<lang Icon>every x := L[i := 1 to *L,1 to *L[i]] do
if x = 20 then break write("L[",i,",",j,"]=20") # more succinctly
every if !!L = 20 then break write("Found !!L=20") # even more so (but looses the values of i and j</lang>
Unicon
The Icon solution works in Unicon.
J
In J, using loops is usually a bad idea.
Here's how the problem statement (ignoring the "requirement" for loops) could be solved, without loops:
<lang J>use=: ({.~ # <. 1+i.&20)@:,</lang>
Here's how the problem could be solved, using loops:
<lang J>doubleLoop=:verb define
for_row.i.#y do.
for_col.i.1{$y do.
smoutput t=.(<row,col) { data
if.20=t do.return.end.
end.
end.
)</lang>
The first approach is probably a couple thousand times faster than the second.
In real life, good problem definitions might typically involve "use cases" (which are specified in terms of the problem domain, instead in terms of irrelevant details). Of course "Rosetta Code" is about how concepts would be expressed in different languages. However, even here, tasks which dwell on language-specific issues are probably not a good use of people's time.
Java
<lang java>import java.util.Random;
public class NestedLoopTest {
public static final Random gen = new Random();
public static void main(String[] args) {
int[][] a = new int[10][10];
for (int i = 0; i < a.length; i++)
for (int j = 0; j < a[i].length; j++)
a[i][j] = gen.nextInt(20) + 1;
Outer:
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a[i].length; j++) {
System.out.print(" " + a[i][j]);
if (a[i][j] == 20)
break Outer;
}
System.out.println();
}
System.out.println();
}
}</lang>
JavaScript
Demonstrates use of break with a label.
Uses print() function from Rhino.
<lang javascript>// a "random" 2-D array
var a = [[2, 12, 10, 4], [18, 11, 9, 3], [14, 15, 7, 17], [6, 19, 8, 13], [1, 20, 16, 5]];
outer_loop: for (var i in a) {
print("row " + i);
for (var j in a[i]) {
print(" " + a[i][j]);
if (a[i][j] == 20)
break outer_loop;
}
} print("done");</lang>
Lisaac
<lang Lisaac>Section Header
+ name := TEST_LOOP_NESTED;
- external := `#include <time.h>`;
Section Public
- main <- (
+ a : ARRAY2[INTEGER]; + i, j: INTEGER;
`srand(time(NULL))`;
a := ARRAY2[INTEGER].create(0, 0) to (9, 9);
0.to 9 do { ii : INTEGER;
0.to 9 do { jj : INTEGER;
a.put (`rand()`:INTEGER % 20 + 1) to (ii, jj);
};
};
{ i < 10 }.while_do {
j := 0;
{ j < 10 }.while_do {
' '.print;
a.item(i, j).print;
(a.item(i, j) = 20).if {
i := 999;
j := 999;
};
j := j + 1;
};
i := i + 1;
'\n'.print;
};
'\n'.print;
);</lang>
Logo
<lang logo>make "a mdarray [10 10]
for [j 1 10] [for [i 1 10] [mdsetitem list :i :j :a (1 + random 20)]]
to until.20
for [j 1 10] [
for [i 1 10] [
type mditem list :i :j :a
type "| |
if equal? 20 mditem list :i :j :a [stop]
]
print "||
]
end until.20</lang>
Lua
<lang lua> t = {} for i = 1, 20 do
t[i] = {}
for j = 1, 20 do t[i][j] = math.random(20) end
end function exitable()
for i = 1, 20 do
for j = 1, 20 do
if t[i][j] == 20 then
return i, j
end
end
end
end print(exitable()) </lang>
MOO
<lang moo>a = make(10, make(10)); for i in [1..10]
for j in [1..10] a[i][j] = random(20); endfor
endfor for i in [1..10]
s = "";
for j in [1..10]
s += tostr(" ", a[i][j]);
if (a[i][j] == 20)
break i;
endif
endfor
player:tell(s);
s = "";
endfor player:tell(s);</lang>
OCaml
<lang ocaml># Random.self_init();; - : unit = ()
- let m = Array.make_matrix 10 10 0 ;;
val m : int array array =
[|[|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]|]
- for i = 0 to pred 10 do
for j = 0 to pred 10 do
m.(i).(j) <- 1 + Random.int 20
done;
done;;
- : unit = ()
- try
for i = 0 to pred 10 do
for j = 0 to pred 10 do
Printf.printf " %d" m.(i).(j);
if m.(i).(j) = 20 then raise Exit;
done;
print_newline()
done;
with Exit ->
print_newline()
;;
15 8 15 9 9 6 1 18 6 18
17 1 13 15 13 1 16 4 13 9
15 3 5 19 17 3 1 11 5 2
1 1 6 19 20
- : unit = ()</lang>
Octave
Octave has no way of exiting nested loop; so we need a control variable, or we can use the trick of embedding the loops into a function and use the return statement. (The search for "exactly 20" is changed into a search for "almost 20")
<lang octave>function search_almost_twenty() % create a 100x100 matrix... m = unifrnd(0,20, 100,100); for i = 1:100
for j = 1:100
disp( m(i,j) )
if ( abs(m(i,j) - 20) < 1e-2 )
return
endif
endfor
endfor endfunction
search_almost_twenty()
% avoiding function, we need a control variable. m = unifrnd(0,20, 100,100); innerloopbreak = false; for i = 1:100
for j = 1:100
disp( m(i,j) )
if ( abs(m(i,j) - 20) < 1e-2 )
innerloopbreak = true;
break;
endif
endfor
if ( innerloopbreak )
break;
endif
endfor</lang>
Oz
We can directly access and use the outer loop's break procedure: <lang oz>declare
fun {CreateMatrix Width Height}
Matrix = {List.make Height}
in
for Row in Matrix do
Row = {List.make Width}
for X in Row do
X = {OS.rand} mod 20 +1
end
end
Matrix
end
proc {PrintMatrix Matrix}
%% print until we see 20
for Row in Matrix break:OuterBreak do
for X in Row do
{Show X}
if X == 20 then {OuterBreak} end
end
end
end
in
{PrintMatrix {CreateMatrix 10 10}}</lang>
Perl
<lang perl>my $a = [ map [ map { int(rand(20)) + 1 } 1 .. 10 ], 1 .. 10];
Outer: foreach (@$a) {
foreach (@$_) {
print " $_";
if ($_ == 20) {
last Outer;
}
}
print "\n";
} print "\n";</lang>
PHP
<lang php><?php for ($i = 0; $i < 10; $i++)
for ($j = 0; $j < 10; $j++)
$a[$i][$j] = rand(1, 20);
foreach ($a as $row) {
foreach ($row as $element) {
echo " $element";
if ($element == 20)
break 2; // 2 is the number of loops we want to break out of
}
echo "\n";
} echo "\n"; ?></lang>
PicoLisp
<lang PicoLisp>(for Lst (make (do 10 (link (make (do 10 (link (rand 1 20)))))))
(T
(for N Lst
(printsp N)
(T (= N 20) T) ) ) )</lang>
or: <lang>(catch NIL
(for Lst (make (do 10 (link (make (do 10 (link (rand 1 20)))))))
(for N Lst
(printsp N)
(and (= N 20) (throw)) ) ) )</lang>
PL/I
<lang PL/I>
declare x(20,20) fixed; /* 16 August 2010. */ x = random()*20 + 1;
loops:
do i = 1 to hbound(x,1);
do j = 1 to hbound(x,2);
put (x(i,j));
if x(i,j) = 20 then leave loops;
end;
if x(i,j) = 20 then leave;
end;
</lang>
PureBasic
<lang PureBasic>; Creating and filling array Dim Value(10, 5) For a = 0 To 10
For b = 0 To 5 Value(a, b) = Random(19) + 1 Next
Next
- iterating trough array
For a = 0 To 10
For b = 0 To 5
Debug Value(a, b)
If Value(a, b) = 20
; 2 indicates, that there are two nested lopps to break out
Break 2
EndIf
Next
Next</lang>
Python
Python has only inner loop breaks. Below are two solutions around this problem, the first uses exception handling:
<lang python>import random class Found20(Exception):
pass
number_array = [[random.randrange(1,21) for x in xrange(10)] for y in xrange(10)]
try:
for row in number_array:
for element in row:
print element,
if element == 20:
raise Found20
print
except Found20:
print</lang>
The second uses a flag variable:
<lang python>import random
number_array = [[random.randrange(1,21) for x in xrange(10)] for y in xrange(10)] found20 = False
for row in number_array:
for element in row:
print element,
if element == 20:
found20 = True
break
print
if found20:
break</lang>
The , after print element suppresses printing a line break. The above has been programmed on Python 2.6; I assume it also works on other Python 2.x versions, but it needs some minor changes in Python 3.
But the normal way to solve this problem in Python is to use a return inside a function: <lang python>from random import randint
def do_scan(m):
for row in m:
for item in row:
print item,
if item == 20:
print
return
print
m = [[randint(1, 20) for x in xrange(10)] for y in xrange(10)] do_scan(m)</lang>
R
<lang R>m <- 10 n <- 10 mat <- matrix(sample(1:20L, m*n, replace=TRUE), nrow=m); mat done <- FALSE for(i in seq_len(m)) {
for(j in seq_len(n))
{
cat(mat[i,j])
if(mat[i,j] == 20)
{
done <- TRUE
break
}
cat(", ")
}
if(done)
{
cat("\n")
break
}
}</lang>
REBOL
<lang REBOL>REBOL [ Title: "Loop/Nested" Author: oofoe Date: 2010-01-05 URL: http://rosettacode.org/wiki/Loop/Nested ]
- Number formatting.
zeropad: func [pad n][
n: to-string n insert/dup n "0" (pad - length? n) n]
- Initialize random number generator from current time.
random/seed now
- Create array and fill with random numbers, range 1..20.
soup: array [10 10] repeat row soup [forall row [row/1: random 20]]
print "Loop break using state variable:" done: no for y 1 10 1 [ for x 1 10 1 [ prin rejoin [zeropad 2 soup/:x/:y " "] if 20 = soup/:x/:y [done: yes break] ] prin crlf if done [break] ]
print [crlf "Loop break with catch/throw:"] catch [ for y 1 10 1 [ for x 1 10 1 [ prin rejoin [zeropad 2 soup/:x/:y " "] if 20 = soup/:x/:y [throw 'done] ] prin crlf ] ] prin crlf</lang>
Output:
Loop break using state variable: 15 09 11 03 17 07 09 16 03 07 03 15 04 06 13 05 10 06 02 14 17 05 06 12 03 19 03 03 17 04 17 15 14 17 15 07 06 16 13 11 02 08 12 16 04 14 03 19 02 02 02 13 14 14 15 01 10 07 17 03 07 17 20 Loop break with catch/throw: 15 09 11 03 17 07 09 16 03 07 03 15 04 06 13 05 10 06 02 14 17 05 06 12 03 19 03 03 17 04 17 15 14 17 15 07 06 16 13 11 02 08 12 16 04 14 03 19 02 02 02 13 14 14 15 01 10 07 17 03 07 17 20
REXX
Standard REXX has a work around for this: <lang rexx>do i = 1 to 10
do j = 1 to 10
numbers.i.j = random(1, 20)
numbers.i.0 = j
end
numbers.0 = i
end
do i = 1 to numbers.0
do j = 1 to numbers.i.0
say numbers.i.j
if numbers.i.j = 20 then
signal mylabel
end
end
mylabel:</lang>
:
<lang rexx>numbers = .array~new() do i = 1 to 10
do j = 1 to 10
numbers[i,j] = random(1, 20)
end
end
do i = 1 to numbers~dimension(1)
do j = 1 to numbers~dimension(2)
say numbers[i,j]
if numbers[i,j] = 20 then
leave i
end
end</lang>
Ruby
As the break command only jumps out of the innermost loop, this task requires Ruby's catch/throw functionality.
<lang ruby>srand
ary = (1..20).to_a.shuffle.each_slice(4).to_a
p ary
catch :found_it do
for row in ary
for element in row
print "%2d " % element
throw :found_it if element == 20
end
puts ","
end
end
puts "done"</lang>
[[2, 12, 10, 4], [18, 11, 9, 3], [14, 15, 7, 17], [6, 19, 8, 13], [1, 20, 16, 5]] 2 12 10 4 , 18 11 9 3 , 14 15 7 17 , 6 19 8 13 , 1 20 done
Sather
<lang sather>class MAIN is
main is
a:ARRAY2{INT} := #(10,10);
i, j :INT;
RND::seed(1230);
loop i := 0.upto!(9);
loop j := 0.upto!(9);
a[i, j] := RND::int(1, 20);
end;
end;
loopthis ::= true;
loop i := 0.upto!(9); while!( loopthis );
loop j := 0.upto!(9);
#OUT + " " + a[i, j];
if a[i, j] = 20 then
loopthis := false; break!; end;
end; end; end;
end;</lang>
Scheme
Using call/cc: <lang scheme> (call-with-current-continuation
(lambda (return) (for-each (lambda (a)
(for-each (lambda (b) (cond ((= 20 b) (newline) (return)) (else (display " ")(display b)))) a) (newline)) array))) </lang> Using tail-call: <lang scheme> (let loop ((a array))
(if (pair? a)
(let loop2 ((b (car a)))
(cond ((null? b) (newline) (loop (cdr a))) ((= 20 (car b)) (newline)) (else (display " ")(display (car b)) (loop2 (cdr b))))))) </lang>
Smalltalk
Smalltalk has no ways of escaping from loops (single or nested), even if it is possible to extend its iteration capabilities in several ways. The following code implements a BiArray class with a method that allows iteration over the elements (by columns and then by rows) and execution of a block if a condition is true.
<lang smalltalk>"this simple implementation of a bidimensional array
lacks controls over the indexes, but has a way of iterating over array's elements, from left to right and top to bottom"
Object subclass: BiArray [
|cols rows elements|
BiArray class >> columns: columns rows: howManyRows [
^ super basicNew init: columns per: howManyRows
]
init: columns per: howManyRows [
cols := columns.
rows := howManyRows.
elements := Array new: ( columns * howManyRows )
]
calcIndex: biIndex [ "column, row (x,y) to linear"
^ ( (biIndex at: 1) + (((biIndex at: 2) - 1) * cols) )
]
at: biIndex [ "biIndex is an indexable containing column row"
^ elements at: (self calcIndex: biIndex).
]
directAt: i [ ^ elements at: i ]
at: biIndex put: anObject [
elements at: (self calcIndex: biIndex) put: anObject
]
whileTrue: aBlock do: anotherBlock [
|i lim|
i := 1. lim := rows * cols.
[ ( i <= lim )
& (aBlock value: (self directAt: i) )
] whileTrue: [
anotherBlock value: (self directAt: i).
i := i + 1.
]
]
].
|biarr| biarr := BiArray columns: 10 rows: 10.
"fill the array; this illustrates nested loop but not how to
escape from them"
1 to: 10 do: [ :c |
1 to: 10 do: [ :r |
biarr at: {c . r} put: (Random between: 1 and: 20)
]
].
"loop searching for 20; each block gets the element passed as argument" biarr whileTrue: [ :v | v ~= 20 ]
do: [ :v | v displayNl ]</lang>
Tcl
Tcl only supports single-level breaks; exiting more deeply nested looping requires the use of exceptions, which are considerably more verbose before Tcl 8.6.
<lang tcl>set ary [subst [lrepeat 10 [lrepeat 5 {[expr int(rand()*20+1)]}]]]
try {
foreach row $ary {
foreach col $row {
puts -nonewline [format %3s $col]
if {$col == 20} {
throw MULTIBREAK "we're done"
}
}
puts ,
}
} trap MULTIBREAK {} {} puts " done"</lang> Sample output:
12 13 14 13 15, 1 14 7 16 3, 12 11 5 1 9, 12 5 1 4 2, 6 11 11 4 11, 7 14 20 done
TI-89 BASIC
The Stop statement exits the containing program.
<lang ti89b>Prgm
Local mat,i,j
© randMat(5, 5) exists but returns -9 to 9 rather than 1 to 20
newMat(5, 5) → mat
For i,1,rowDim(mat)
For j,1,colDim(mat)
rand(20) → mat[i,j]
EndFor
EndFor
Disp mat
Pause "Press a key."
ClrIO
For i,1,rowDim(mat)
For j,1,colDim(mat)
If mat[i,j] = 20 Then
Stop
Else
Output i*8, j*18, mat[i,j]
EndIf
EndFor
EndFor
EndPrgm</lang>