PAT乙级题目-- 有理数加法

#include<stdio.h>

int main(){
    int a1,b1,a2,b2,c1,c2;
int i=2;
     scanf("%d/%d %d/%d",&a1,&b1,&a2,&b2);
     if(b1!=b2){
         a1=a1*b2;
         a2=a2*b1;
         b2=b2*b1;
         c1=a1+a2;
         c2=b2;
     }
     else{
         c1=a1+a2;
         c2=b2;
     }
//     printf("%d/%d",c1,c2);
     while(i<=c2){
             if(c1%i==0&&c2%i==0){
                 c1=c1/i;
                 c2=c2/i;
             }
             else
                 i++;
         }
         if(c2==1){
             printf("%d",c1);
         }
         else
             printf("%d/%d",c1,c2);
     
     
}