ACM 2260 http://acm.pku.cn/JudgeOnline/problem?id=2260

#include <iostream>
using namespace std;
int main ()
{
    int n;
bool a[100][100];
for(int i=0;i<100;i++)
{
   cin >>n;
      if (n==0)
   break;
   int o=0,q=0,p=0,x=0,y=0;
   for (int j=0;j<n;j++)
    for (int k=0;k<n;k++)
    {
     cin >>a[j][k];
    }
    
    for (int l=0;l<n;l++)
    {
     int sum1=0;
     for (int m=0;m<n;m++)
     {
      sum1=sum1+a[l][m];     
     }
     if (sum1%2!=0)
     {
      q++;
      x=l+1;
     }

    }     
    for (int ll=0;ll<n;ll++)
    {
     int sum2=0;
     for (int mm=0;mm<n;mm++)
     {
      sum2=sum2+a[mm][ll];     
     }
     if (sum2%2!=0)
     {
      o++;
      y=ll+1;
     }

    }
    if (o==1&&q==1)
     cout<<"Change bit ("<<x<<","<<y<<")"<<endl;
    else if (o==0&&q==0)
     cout <<"OK"<<endl;
    else 
     cout <<"Corrupt"<<endl;

}
return 0;
}