Compilare: main.cpp: In function 'void bfs(int, int)': main.cpp:12:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | for(int i=0;i<a[i].size();i++) | ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:48:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | for(int i=0;i<a[x].size();i++) | ~^~~~~~~~~~~~