【gcd】辗转相除法

 #include<stdio.h>

 int gcd(int a, int b)
 {
     int c;
     while(b)
     {
         c = a % b;
         a = b;
         b = c;
     }
     return a;
 }

 int main()
 {
     int a, b;
     while(scanf("%d%d", &a, &b) != EOF)
     {
         printf("%d\n", gcd(a, b));
     }
     return ;
 }