Compilare: main.cpp: In function 'bool bfs()': main.cpp:29:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 29 | for (int i = 0; i < ad[x].size(); ++i) { | ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:53:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 53 | for (int i = 0; i < ad[n].size(); ++i) { | ~~^~~~~~~~~~~~~~ main.cpp:72:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 72 | for (int i = 1; i < ad.size(); ++i) { | ~~^~~~~~~~~~~ main.cpp:74:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 74 | for (int j = 0; j < ad[i].size(); ++j) { | ~~^~~~~~~~~~~~~~