func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 1e9 + 7;   const long long N = 50;   const long long INF = 1e10;   vector<string> mat(N);   int n, r1, c1, r2, c2;   vector<vector<bool>> visited(N, vector<bool>(N));   void dfs(int i, int j, vector<pair<int, int>> &s) {     visited[i][j] = true;     s.push_back({i, j});     if (i + 1 < n and !visited[i + 1][j] and mat[i + 1][j] ==  0 )       dfs(i + 1, j, s);     if (i - 1 >= 0 and !visited[i - 1][j] and mat[i - 1][j] ==  0 )       dfs(i - 1, j, s);     if (j + 1 < n and !visited[i][j + 1] and mat[i][j + 1] ==  0 )       dfs(i, j + 1, s);     if (j - 1 >= 0 and !visited[i][j - 1] and mat[i][j - 1] ==  0 )       dfs(i, j - 1, s);   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(NULL);     vector<pair<int, int>> s, f;     cin >> n >> r1 >> c1 >> r2 >> c2;     for (int i = 0; i < n; i++) cin >> mat[i];     dfs(r1 - 1, c1 - 1, s);     if (!visited[r2 - 1][c2 - 1]) dfs(r2 - 1, c2 - 1, f);     if (f.size() == 0) {       cout << 0;       return 0;     }     int ans = INT_MAX;     for (auto i : s) {       for (auto j : f)         ans = min(ans, (i.first - j.first) * (i.first - j.first) +                            (i.second - j.second) * (i.second - j.second));     }     cout << ans;   }   