编辑代码

#include <stdio.h>  
  
int GCD(int l, int w) {  
    while (w != 0) {  
        int r = l % w;  
        l = w;  
        w = r;  
    }  
    return l;  
}  
  
int main() {  
    printf("%d\n", GCD(640, 1680));  
    printf("%d\n", GCD(1680, 640));  
    return 0;  
}