Compilare: main.cpp: In function 'int main()': main.cpp:48:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | if (x < 0 || x >= adj.size() || y < 0 || y >= adj.size()) | ~~^~~~~~~~~~~~~ main.cpp:48:56: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | if (x < 0 || x >= adj.size() || y < 0 || y >= adj.size()) | ~~^~~~~~~~~~~~~