Euler-sol-5
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Solutions for Problem 5
What is the smallest number that is evenly divisible by all of the numbers from 1 to 20?
Perl by Stryker
Runtime: ??ms
#!/usr/bin/perl # http://projecteuler.net/index.php?section=problems&id=5 # written in about 10 minutes. # no optimisations # $x=21; while ($x) { $a=$x%11; if($a==0){ $b=$x%12; if($b==0){ $c=$x%13; if($c==0){ $d=$x%14; if($d==0){ $e=$x%15; if($e==0){ $f=$x%16; if($f==0){ $g=$x%17; if($g==0){ $h=$x%18; if($h==0){ $i=$x%19; if($i==0){ $j=$x%20; if($j==0){ print $x."\n"; exit; } } } } } } } } } } $x++; }
C++ by SanguineV
Runtime: 7ms
// Many numbers can be excluded as any factors will also be factors of other numbers in the range 1-20
// Number: covered by
// 24 : 2,3,4,6,8,12
// Primes: 2,3,5,7,11,13,17,19
// Intersect these two and they cover:
// 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
#include <iostream>
using namespace std;
int main(char* argv, int argc) {
long res = 24*2*3*5*7*11*13*17*19;
cout << res << endl;
}
Python by Althalus
Forgot to note the runtime.
import time
start_time = time.time()
start=20
done=0
while done==0:
done=1
i=2
#Starting at 20 and going up by 20. Therefore, will be divisible by 20, and subsequently, factors of 20. (10, 5, 4, 2)
start=start+20
if start%19 != 0: #Prime.
done=0
if start%17 != 0: #Prime.
done=0
if start%18 != 0: #Also divisibly by 9, 6, 3
done=0
if start%16 != 0: #Also divisibly by 8
done=0
if start%15 != 0:
done=0
if start%14 != 0: #ALso divisible by 4.
done=0
if start%13 != 0: #Prime
done=0
if start%12 != 0:
done=0
if start%11 != 0: #Prime
done=0
print(start)
run_time = time.time() - start_time
print ('Run time: ', run_time, ' seconds',)
Excel VBA by mmaster
1 minute 38 seconds
Sub ProblemFive()
Dim max
Dim MagicNumber As Integer
MagicNumber = 20
Dim k
max = 1
For i = 1 To MagicNumber
max = max * i
Next i
For i = MagicNumber + 1 To max
For j = 2 To MagicNumber
k = 0
If i Mod j <> 0 Then
Exit For
End If
k = j
Next j
If k = MagicNumber Then
MsgBox i
Exit Sub
End If
Next i
End Sub
Haskell by SanguineV
Runtime: 5 ms
main = print (head (filter (\x -> all (\z -> mod x z == 0) [12,16,18,20])
[2*3*5*7*11*13*17*19*i | i <- [1..]]))
Javascript by ctd
Runtime: 7.9 seconds
var i = 0, even = false;
while (!even) {
i++;
even = evenlyDivides(i, 20);
}
console.log(i);
function evenlyDivides(num, den) {
if (den == 0) return true;
if (num % den == 0)
return evenlyDivides(num, den-1);
else
return false;
}
