atDPO.cpp

/*
 * Contest : AtCoder Educational DP Contest
 * Problem : O - Matching
 * Link    : https://atcoder.jp/contests/dp/tasks/dp_o
 */

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

#define fastio ios::sync_with_stdio(0); cin.tie(0);

int main() {
  fastio
  
  int n, mod = 1e9+7;
  cin >> n;
  bool grid[n][n];
  vector <int> dp(1 << n);
  
  for (int i = 0; i < n; ++i) 
    for (int j = 0; j < n; ++j) 
      cin >> grid[i][j];
    
  dp[0] = 1;
  for (int mask = 0; mask < (1 << n); ++mask) {
    int row = __popcount((unsigned int)mask);
    for (int i = 0; i < n; ++i) {
      if (mask & (1 << i) || !grid[row][i]) continue;
      
      dp[mask | (1 << i)] = (dp[mask | (1 << i)] + dp[mask]) % mod;
    }
  }
  cout << dp[(1 << n) - 1] << '\n';
  
  return 0;
}