Envío 5485

Código

#include <bits/stdc++.h>
#define REP(i,n) for(int i=0; i<n;i++)
#define pb push_back
#define ff first
#define ss second
#define ii pair<int,int>
#define vi vector<int>
#define vii vector<ii>
#define lli long long int
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
ostream& operator<<(ostream& os, const vector<int> &v){
    for(auto const &i: v){
        os<<i<<" ";
    }
    os<<endl;
    return os;
}
const lli mod=(1e9)+7;
const int N = 1e4+1;
int main(){
    fast_io;
    int n;cin>>n;
    int m[n][n];
    REP(i,n){
        REP(j,n){
            cin>>m[i][j];
        }
    }
    int ans[6] = {0};
    REP(i,n){

        ans[0] += m[i][0];
        ans[1] += m[i][n-1];

        ans[2] += m[0][i];
        ans[3] += m[n-1][i];

        ans[4] += m[i][i];
        ans[5] += m[n-1-i][i];
    }
    int prev = ans[0];
    bool flag = true;
    REP(i,6){
        //cout<<ans[i]<<endl;
        if(ans[i]!=prev)flag = false;
    }
    if(flag)cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}