辗转除法求模

#include <stdio.h>void main(){int i,n=4,b,a,r;scanf("%d",&b);for(i=0;i<n-1;i++){scanf("%d",&a);r=a%b;while (r!=0){a=b;b=r;r=a%b;}}printf("%d\n",b);}//GCD(a,b,c)=GCD(GCD(a,b),c) 辗转除法求模