Envío 6405

Código

#include <bits/stdc++.h>
using namespace std;

int main() {
  int n; cin>>n;
  int arr[n][n];
  int firstDiagonal = 0;
  int secondDiagonal = 0;
  int sum;
  int x = n-1;
  bool isMagic = true;
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < n; j++) {
      cin>>arr[i][j];
    }
  }
  for(int i = 0; i < n; i++) {
    int rowSum = 0;
    int colSum = 0;
    firstDiagonal += arr[i][i];
    secondDiagonal += arr[i][x];
    for(int j = 0; j < n; j++) {
      rowSum += arr[i][j];
      colSum += arr[j][i];
    }
    if(i > 0) {
      if(!(rowSum == colSum && colSum == sum)) {
        isMagic = false;
        break;
      }
    } else {
      if(rowSum == colSum) sum = rowSum;
      else {
        isMagic = false;
        break;
      }
    }
    x--;
  }
  if(isMagic) {
    isMagic = firstDiagonal == secondDiagonal && secondDiagonal == sum;
  }
  if(isMagic) cout<<"Yes"<<endl;
  else cout<<"No"<<endl;
  return 0;
}