Envío 890

Código

#include <iostream>
#include <vector>

using namespace std;

int main() {
  int n, sum, magic=-1;
  cin >> n;

  int square[n][n];

  int cols[n], rows[n], diag1=0, diag2=0;

  for(int row=0;row<n;row++){
    rows[row]= 0;
    for(int col=0;col<n;col++){
      cin >> square[row][col];
      int current = square[row][col];

      if(row == 0){
        cols[col] = current;
      }
      else{
        cols[col] += current;
      }

      rows[row] += current;
      if(row==col){
        diag1+=current;
      }

      if(col== (n-1-row) ){
        diag2+=current;
      }

    }
  }

  magic = rows[0];


  if(magic != diag1){
    // cout << "diag1 " << diag1 << endl;
    cout << "NO" <<endl;
    return 0;
  }


  if(magic != diag2){
    //cout << "diag " << diag2 << endl;
    cout << "NO" <<endl;
    return 0;
  }

  for(int row=1;row<n;row++){
    if(rows[row]!=magic){
      // cout << "row " << row << endl;
      cout << "NO" <<endl;
      return 0;
    }
  }

  for(int col=1;col<n;col++){
    if(cols[col]!=magic){
      // cout << "col " << col << endl;
      cout << "NO" <<endl;
      return 0;
    }
  }

  cout << "YES" << endl;

}