Compilare: main.cpp: In function 'void bfs(int, int, std::vector<std::vector<char> >&, std::vector<std::vector<int> >&)': main.cpp:25:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 25 | if (neigh_x < 0 || neigh_x >= adj.size() | ~~~~~~~~^~~~~~~~~~~~~ main.cpp:26:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | || neigh_y < 0 || neigh_y >= adj.size()) | ~~~~~~~~^~~~~~~~~~~~~