Envío 2656

Código

#include <bits/stdc++.h>

#define fi first
#define se second
#define forn(i,n) for(int i=0; i< (int)n; ++i)
#define for1(i,n) for(int i=1; i<= (int)n; ++i)
#define fore(i,l,r) for(int i=(int)l; i<= (int)r; ++i)
#define ford(i,n) for(int i=(int)(n) - 1; i>= 0; --i)
#define fored(i,l,r) for(int i=(int)r; i>= (int)l; --i)
#define pb push_back
#define el '\n'
#define d(x) cout<< #x<< " " << x<<el
#define ri(n) scanf("%d",&n)
#define sz(v) ((int)v.size())
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()

using namespace std;

typedef long long ll;
typedef double ld;
typedef pair<int,int> ii;
typedef pair<char,int> pci;
typedef tuple<int, int, int> tiii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;

const ll inf = 1e18;
const int nax = 1e5+200;
const double mpi = acos(-1);
const double eps= 1e-10;

int dr[] = {1,-1,0, 0,1,-1,-1, 1}; // trick to explore an implicit 2D grid
int dc[] = {0, 0,1,-1,1, 1,-1,-1};

int main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL); cout.tie(NULL);
  cout<< setprecision(20)<< fixed;
  int n;
  cin>> n;
  int mat[n][n];
  forn(i,n){
    forn(j,n){
      cin>> mat[i][j];
    }
  }
  int f = 1e9;
  string ans = "Yes";
  forn(i,n){
    int sum = 0;
    forn(j,n){
      sum += mat[i][j];
    }
    if(f==1e9 || sum==f) f = sum;
    else{
      ans = "No";
    }
  }

  forn(j,n){
    int sum = 0;
    forn(i,n){
      sum += mat[i][j];
    }
    if(sum!=f){
      ans = "No";
    }
  }
  int fix = 0;
  forn(j,2){
    int sum = 0;
    forn(i,n){
      sum += mat[i][abs(fix-i)];
    }
    if(sum!=f){
      ans = "No";
    }
    fix += n-1;
  }
  cout<< ans<<el;
}