Greatest common divisor
This task requires the finding of the greatest common divisor of two integers.
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
You are encouraged to solve this task according to the task description, using any language you may know.
Ada
with Ada.Text_Io; use Ada.Text_Io; procedure Gcd_Test is function Gcd (A, B : Integer) return Integer is begin if A = 0 then return B; end if; if B = 0 then return A; end if; if A > B then return Gcd(B, A mod B); else return Gcd(A, B mod A); end if; end Gcd; begin Put_Line("GCD of 100, 5 is" & Integer'Image(Gcd(100, 5))); Put_Line("GCD of 5, 100 is" & Integer'Image(Gcd(5, 100))); Put_Line("GCD of 7, 23 is" & Integer'Image(Gcd(7, 23))); end Gcd_Test;
ALGOL 68
PROC gcd = (INT a, b) INT: ( IF a = 0 THEN b ELIF b = 0 THEN a ELIF a > b THEN gcd(b, a MOD b) ELSE gcd(a, b MOD a) FI ); main : ( INT a = 33, b = 77; printf(($x"The gcd of"g" and "g" is "gl$,a,b,gcd(a,b))); INT c = 49865, d = 69811; printf(($x"The gcd of"g" and "g" is "gl$,c,d,gcd(c,d))) )
The output is:
The gcd of +33 and +77 is +11 The gcd of +49865 and +69811 is +9973
Forth
: gcd ( a b -- n ) begin dup while tuck mod repeat drop ;
J
x+.y
Java
Iterative
public static long gcd(long a, long b){ long factor= 0; factor= Math.max(a, b); for(long loop= factor;loop > 1;loop--){ if(a % loop == 0 && b % loop == 0){ return loop; } } return 1; }
Recursive
public static long gcd(long a, long b){ if(a == 0) return b; if(b == 0) return a; if(a > b) return gcd(b, a % b); return gcd(a, b % a); }
Python
Iterative
def gcd_iter(u, v): while v: u, v = v, u % v return abs(u)
Recursive
Interpreter: Python 2.5
def gcd(u, v): return gcd(v, u % v) if v else abs(u)
Tests
>>> gcd(0,0) 0 >>> gcd(0, 10) == gcd(10, 0) == gcd(-10, 0) == gcd(0, -10) == 10 True >>> gcd(9, 6) == gcd(6, 9) == gcd(-6, 9) == gcd(9, -6) == gcd(6, -9) == gcd(-9, 6) == 3 True >>> gcd(8, 45) == gcd(45, 8) == gcd(-45, 8) == gcd(8, -45) == gcd(-8, 45) == gcd(45, -8) == 1 True >>> gcd(40902, 24140) # check Knuth :) 34