func_code_string: #include <bits/stdc++.h>   using namespace std;   string b[51];   bool check(pair<int, int> f, pair<int, int> s) {     bool r1 = true, r2 = true, c1 = true, c2 = true;     for (int i = f.first; i <= s.first; i++) {       if (b[i][f.second] ==  W ) c1 = false;       if (b[i][s.second] ==  W ) c2 = false;     }     for (int i = s.first; i <= f.first; i++) {       if (b[i][f.second] ==  W ) c1 = false;       if (b[i][s.second] ==  W ) c2 = false;     }     for (int i = f.second; i <= s.second; i++) {       if (b[f.first][i] ==  W ) r1 = false;       if (b[s.first][i] ==  W ) r2 = false;     }     for (int i = s.second; i <= f.second; i++) {       if (b[f.first][i] ==  W ) r1 = false;       if (b[s.first][i] ==  W ) r2 = false;     }     return (c1 && r2) || (c2 && r1);   }   vector<pair<int, int> > v;   int main() {     int r, c;     cin.tie(0);     cin >> r >> c;     for (int i = 0; i < r; i++) {       cin >> b[i];       for (int j = 0; j < c; j++)         if (b[i][j] ==  B ) v.push_back({i, j});     }     int sz = v.size();     for (int i = 0; i < sz; i++)       for (int j = i + 1; j < sz; j++) {         if (!check(v[i], v[j])) {           cout <<  NO ;           return 0;         };       }     cout <<  YES ;     return 0;   }   