POJ 1331 Multiply

#include <iostream>
using namespace std;

int main(){
    int t;
    bool flag;
    cin>>t;
    char p[35],q[35],r[35];
    int p2,q2,r2;
    while(t--){
        scanf("%s %s %s", p, q, r);
        flag=false;
        for(int i=2; i<=16; i++){
            p2 = strtol(p, NULL, i);
            q2 = strtol(q, NULL, i);
            r2 = strtol(r, NULL, i);
            if(p2*q2==r2 && p2!=0 && q2!=0){
                cout<<i<<endl;
                flag=true;
                break;              
            }
        }
        if(flag==false)
            cout<<"0"<<endl;
    }  
    return 0;
}
  

 G++  Compile Error 

C++    AC

http://my.oschina.net/dianpaopao/blog/82403