求最大公约数

//求最大公约数//利用欧几里得算法（也叫辗转相除法）#include "stdafx.h"//递归程序unsigned int GcdRecursively (unsigned int x, unsigned int y){if (x == 0 || y == 0)return x+y;//return非0值return GcdRecursively(y,x%y);}//循环程序unsigned int GcdIteratively (unsigned int x, unsigned int y){if (x == 0 || y == 0)return 0;unsigned int temp = x % y;while (temp){x = y;y = temp;temp = x % y;}return y;}int _tmain(int argc, _TCHAR* argv[]){unsigned int x = 90;unsigned int y = 60;unsigned int gcd = GcdRecursively(x,y);gcd = GcdIteratively(x,y);return 0;}

但是循环程序不够简洁，有重复的部分。这样写更好：

unsigned int GcdIteratively2 (unsigned int x, unsigned int y){if (x == 0 || y == 0)return 0;unsigned int remain = 0;while (y){remain = x % y;x = y;y = remain;}return x;}