func_code_string: #include <bits/stdc++.h>   using namespace std;   long long global = 0;   void test_case(long long);   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     long long t;     int yes = 1;     if (yes)       cin >> t;     else       t = 1;     for (long long T = 0; T < t; T++) {       test_case(T);     }     return 0;   }   void test_case(long long T) {     long long n, m;     cin >> n >> m;     vector<string> vec(n);     for (long long(i) = 0; (i) < n; (i)++) {       cin >> vec[i];     }     vector<long long> x = {0, 1, 0, -1}, y = {1, 0, -1, 0};     long long g = 0;     for (long long(i) = 0; (i) < n; (i)++) {       for (long long(j) = 0; (j) < m; (j)++) {         if (vec[i][j] ==  G ) g++;         if (vec[i][j] ==  B ) {           for (long long k = 0; k < 4; k++) {             long long idx = i + x[k];             long long jdx = j + y[k];             if (idx >= 0 && idx < n && jdx >= 0 && jdx < m) {               if (vec[idx][jdx] ==  G ) {                 cout <<  no  << endl;                 return;               } else if (vec[idx][jdx] ==  . ) {                 vec[idx][jdx] =  # ;               }             }           }         }       }     }     queue<pair<long long, long long>> q;     q.push(pair<long long, long long>(n - 1, m - 1));     map<pair<long long, long long>, long long> v;     v[pair<long long, long long>(n - 1, m - 1)]++;     long long vg = 0;     while (!q.empty()) {       auto f = q.front();       q.pop();       if (vec[f.first][f.second] ==  G )         vg++;       else if (vec[f.first][f.second] ==  # )         break;       for (long long k = 0; k < 4; k++) {         long long idx = f.first + x[k];         long long jdx = f.second + y[k];         if (idx >= 0 && idx < n && jdx >= 0 && jdx < m) {           if (vec[idx][jdx] ==  #  || vec[idx][jdx] ==  B ) continue;           if (!v[pair<long long, long long>(idx, jdx)]) {             v[pair<long long, long long>(idx, jdx)]++;             q.push(pair<long long, long long>(idx, jdx));           }         }       }     }     if (vg == g)       cout <<  yes  << endl;     else       cout <<  no  << endl;   }   