Envío 2217

Código

#include <iostream>
#include <vector>
#include <map>
using namespace std;

int main()
{
    int num = 0, a , b, sum;
    cin >> num;
    int matriz[num][num];

    for (int i=0;i<num;i++){
        for (int j=0;j<num;j++){
            cin >> a;
            matriz[i][j] = a;
        }
    }

    bool flag = false;

    for (int i=0;i<num;i++){
        sum = 0;
        for (int j=0;j<num;j++){
            sum += matriz[i][j];
        }
        if(i==0) a=sum;
        else if (a!=sum) flag= true;
    }
   // cout << "--" << a << "--" << flag << endl;

    for (int i=0;i<num;i++){
        sum = 0;
        for (int j=0;j<num;j++){
            sum += matriz[j][i];
        }
        if(i==0) a=sum;
        else if (a!=sum) flag= true;
    }
 //   cout << "--" << a << "--" << flag << endl;
    sum = a;

    a = 0;
    b = 0;
    for (int i=0,j=num-1;i<num;i++,j--){
        a += matriz[i][i];
        b += matriz[i][j];
    }
    if (a!=sum) flag= true;
    if (b!=sum) flag= true;
//cout << "--" << a << "--" << flag << endl;
//cout << "--" << b << "--" << flag << endl;

    if(flag) cout << "No" << endl;
    else cout << "Yes" << endl;
    return 0;
}