#include<stdio.h>int main(){ int x, y, m, n; printf("请输入两个数:"); scanf("%d%d", &x, &y); m = x, n = y; while (x!=y) //这里的“!”有什么作用? { if (x>y) x = x-y; else y = y-x; } printf("最大公约数是: %d\n", x); return 0;}