Largest five adjacent number
Generate random 1000-digit number.
Find the five adjacent digits in the 1000-digit number that form the largest 5-digit number.
- Task
- Extra credit
Find the five adjacent digits in the 1000-digit number that form the smallest 5-digit number.
ALGOL 68
Adding the minimum number for good measure... <lang algol68>BEGIN # generate 1000 random digits and find the largest/smallest numbers formed from 5 consecutive digits #
[ 1 : 1000 ]CHAR digits; FOR i TO UPB digits DO digits[ i ] := REPR ( ENTIER ( next random * 10 ) + ABS "0" ) OD; STRING max number := digits[ 1 : 5 ]; STRING min number := digits[ 1 : 5 ]; FOR i FROM 2 TO UPB digits - 4 DO STRING next number = digits[ i : i + 4 ]; IF next number > max number THEN # found a new higher number # max number := next number FI; IF next number < min number THEN # found a new lower number # min number := next number FI OD; print( ( "Largest 5 consecutive digits from 1000 random digits: ", max number, newline ) ); print( ( "Smallest 5 consecutive digits from 1000 random digits: ", min number, newline ) )
END</lang>
- Output:
Largest 5 consecutive digits from 1000 random digits: 99987 Smallest 5 consecutive digits from 1000 random digits: 00119
APL
<lang apl>⌈/((⊣+10×⊢)/(⌽↓))⌺5⊢(-⎕IO)+?1000/10</lang>
- Output:
(example)
99994
AWK
<lang AWK>
- syntax: GAWK -f LARGEST_FIVE_ADJACENT_NUMBER.AWK
BEGIN {
limit = 1000 width = 5 max_n = 0 for (i=1; i<=width; i++) { min_n = min_n "9" } srand() for (i=1; i<=limit; i++) { digits = digits int(rand() * 10) } for (i=1; i<=limit-width+1; i++) { n = substr(digits,i,width) if (n > max_n) { max_n = n max_pos = i } if (n < min_n) { min_n = n min_pos = i } } printf("look for %d digit number using %d digits\n",width,limit) printf("largest %0*d in positions %d-%d\n",width,max_n,max_pos,max_pos+width-1) printf("smallest %0*d in positions %d-%d\n",width,min_n,min_pos,min_pos+width-1) exit(0)
} </lang>
- Output:
look for 5 digit number using 1000 digits largest 99873 in positions 300-304 smallest 00099 in positions 697-701
BQN
<lang bqn>⌈´(⊣+10×⊢)˝⌽⍉5↕1000 •rand.Range 10</lang>
- Output:
(example)
99991
C
<lang c>#include <stdio.h>
- include <stdlib.h>
- include <stdint.h>
- include <time.h>
- define DIGITS 1000
- define NUMSIZE 5
uint8_t randomDigit() {
uint8_t d; do {d = rand() & 0xF;} while (d >= 10); return d;
}
int numberAt(uint8_t *d, int size) {
int acc = 0; while (size--) acc = 10*acc + *d++; return acc;
}
int main() {
uint8_t digits[DIGITS]; int i, largest = 0; srand(time(NULL)); for (i=0; i<DIGITS; i++) digits[i] = randomDigit(); for (i=0; i<DIGITS-NUMSIZE; i++) { int here = numberAt(&digits[i], NUMSIZE); if (here > largest) largest = here; }
printf("%d\n", largest); return 0;
}</lang>
- Output:
(example)
99931
F#
<lang fsharp> // Largest five adjacent number. Nigel Galloway: September 28th., 2021 let n()=let n()=System.Random().Next(10) in Seq.unfold(fun g->Some(g,(g%10000)*10+n()))(n()*10000+n()*1000+n()*100+n()*10+n()) printfn $"Largest 5 adjacent digits are %d{(n()|>Seq.take 995|>Seq.max)}" </lang>
- Output:
Largest 5 adjacent digits are 99914
Factor
<lang factor>USING: grouping io math.functions prettyprint random sequences ;
1000 10^ random unparse 5 <clumps> supremum print</lang>
- Output:
99987
Go
<lang go>package main
import (
"fmt" "math/rand" "rcu" "strings" "time"
)
func main() {
rand.Seed(time.Now().UnixNano()) var sb strings.Builder for i := 0; i < 1000; i++ { sb.WriteByte(byte(rand.Intn(10) + 48)) } number := sb.String() for i := 99999; i >= 0; i-- { quintet := fmt.Sprintf("%05d", i) if strings.Contains(number, quintet) { ci := rcu.Commatize(i) fmt.Printf("The largest number formed from 5 adjacent digits (%s) is: %6s\n", quintet, ci) break } } for i := 0; i <= 99999; i++ { quintet := fmt.Sprintf("%05d", i) if strings.Contains(number, quintet) { ci := rcu.Commatize(i) fmt.Printf("The smallest number formed from 5 adjacent digits (%s) is: %6s\n", quintet, ci) return } }
}</lang>
- Output:
Sample run:
The largest number formed from 5 adjacent digits (99928) is: 99,928 The smallest number formed from 5 adjacent digits (00120) is: 120
J
<lang j>>./5([+10*])/@|:\?1000#10</lang>
- Output:
(example)
99929
Julia
<lang julia>dig = rand(0:9, 1000) @show maximum(evalpoly(10, dig[i:i+4]) for i in 1:length(dig)-4)
</lang>
- Output:
maximum((evalpoly(10, dig[i:i + 4]) for i = 1:length(dig) - 4)) = 99993
Or, using strings, and see Nigel's comment in the discussion:
julia> setprecision(3324) 3324 julia> s = string(BigFloat(pi))[3:end] "141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513282306647093844609550582231725359408128481117450284102701938521105559644622948954930381964428810975665933446128475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588174881520920962829254091715364367892590360011330530548820466521384146951941511609433057270365" ⋯ 180 bytes ⋯ "66940513200056812714526356082778577134275778960917363717872146844090122495343014654958537105079227968925892354201995611212902196086403441815981362977477130996051870721134999999837297804995105973173281609631859502445945534690830264252230825334468503526193118817101000313783875288658753320838142061717766914730359825349042875546873115956286388235378759375195778185778053217122680661300192787661119590921642019898" julia> m, pos = maximum((s[i:i+4], i) for i in 1:length(s)-4) ("99999", 763) julia> println("Maximum is $m at position $pos.") Maximum is 99999 at position 763.
Nim
<lang Nim>import random, strutils
randomize()
const N = 1000 type Digit = 0..9
- Build a 1000-digit number.
var number: array[1..N, Digit] number[1] = rand(1..9) # Make sure the first digit is not 0. for i in 1..N: number[i] = rand(9)
func `>`(s1, s2: seq[Digit]): bool =
## Compare two digit sequences. ## Defining `<` rather than `>` would work too. assert s1.len == s2.len for i in 0..s1.high: let comp = cmp(s1[i], s2[i]) if comp != 0: return comp == 1 result = false
var max = @[Digit 0, 0, 0, 0, 0] for i in 5..N:
let n = number[i-4..i] if n > max: max = n
echo "Largest 5-digit number extracted from random 1000-digit number: ", max.join()</lang>
- Output:
Largest 5-digit number extracted from random 1000-digit number: 99855
Pascal
inspired by Wren
Assumes that there at least is a "1" 4 digits before end of all digits.Else I have to include sysutils and s := Format('%.5d',[i]); for leading zeros.
<lang pascal> var
digits, s : AnsiString; i : LongInt;
begin
randomize; setlength(digits,1000); for i := 1 to 1000 do digits[i] := chr(random(10)+ord('0')); for i := 99999 downto 0 do begin str(i:5,s); if Pos(s,digits) > 0 then break; end; writeln(s, ' found as largest 5 digit number ')
end.</lang>
- Output:
99889 found as largest 5 digit number
Perl
<lang perl>#!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Largest_five_adjacent_number use warnings;
$_ = join , map int rand 10, 1 .. 1e3; my @n; @n[ /(?=(\d{5}))/g ] = (); print "$#n\n";</lang>
- Output:
99899
Python
Seeding the random number generator directly with the datetime stamp produces a warning that it will be deprecated in Python 3.9, hence the "hack" of creating a string out of the timestamp and then seeding with it. <lang Python>
- Aamrun, 5th October 2021
from random import seed,randint from datetime import datetime
seed(str(datetime.now()))
largeNum = [randint(1,9)]
for i in range(1,1000):
largeNum.append(randint(0,9))
maxNum,minNum = 0,99999
for i in range(0,994):
num = int("".join(map(str,largeNum[i:i+5]))) if num > maxNum: maxNum = num elif num < minNum: minNum = num
print("Largest 5-adjacent number found ", maxNum) print("Smallest 5-adjacent number found ", minNum) </lang> Results from multiple runs :
- Output:
Largest 5-adjacent number found 99743 Smallest 5-adjacent number found 102 Largest 5-adjacent number found 99965 Smallest 5-adjacent number found 84 Largest 5-adjacent number found 99808 Smallest 5-adjacent number found 58 Largest 5-adjacent number found 99938 Smallest 5-adjacent number found 10 Largest 5-adjacent number found 99957 Smallest 5-adjacent number found 35
Raku
Show minimum too because... why not?
Use some Tamil Unicode numbers for brevity, and for amusement purposes.
௰ - Tamil number ten ௲ - Tamil number one thousand
Do it 5 times for variety, it's random after all.
<lang perl6>(^௰).roll(௲).rotor(5 => -4)».join.minmax.bounds.put xx 5</lang>
- Sample output:
00371 99975 00012 99982 00008 99995 00012 99945 00127 99972
Ring
<lang ring> digit = "" max = 0 min = 99999 limit = 1000
for n = 1 to limit
rand = random(9) randStr = string(rand) digit += randStr
next
for n = 1 to len(digit)-5
res = substr(digit,n,5) resNum = number(res) if resNum > max max = resNum ok if resNum < min min = res ok
next
see "The largest number is:" + nl see max + nl see "The smallest number is:" + nl see min + nl </lang>
- Output:
The largest number is: 99638 The smallest number is: 00118
Ruby
<lang ruby>digits = %w(0 1 2 3 4 5 6 7 8 9) arr = Array.new(1000){ digits.sample } puts "minimum sequence %s, maximum sequence %s." % arr.each_cons(5).minmax_by{|slice| slice.join.to_i}.map(&:join) </lang>
- Output:
minimum sequence 00096, maximum sequence 99508.
Wren
Very simple approach as there's little need for speed here. <lang ecmascript>import "random" for Random import "/fmt" for Fmt
var rand = Random.new() var digits = List.filled(1000, 0) for (i in 0...999) digits[i] = rand.int(10) var number = digits.join() for (r in [99999..0, 0..99999]) {
var target = (r.from == 0) ? "smallest" : "largest " for (i in r) { var quintet = Fmt.swrite("$05d", i) if (number.contains(quintet)) { Fmt.print("The $s number formed from 5 adjacent digits ($s) is: $,6d", target, quintet, i) break } }
}</lang>
- Output:
Sample output:
The largest number formed from 5 adjacent digits (99830) is: 99,830 The smallest number formed from 5 adjacent digits (00154) is: 154
XPL0
<lang XPL0>char Number(1000); int Num, Max, I, J; [for I:= 0 to 1000-1 do \generate 1000-digit number
Number(I):= Ran(10);
Max:= 0; \find its largest 5-digit number for I:= 0 to 1000-5 do
[Num:= 0; for J:= 0 to 5-1 do Num:= Num*10 + Number(I+J); if Num > Max then Max:= Num; ];
IntOut(0, Max); ]</lang>
- Output:
99930