Compilare: main.cpp: In function 'bool matching(int)': main.cpp:15:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for(int i=0;i<graph[k].size();i++) | ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:52:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | for(int j=0;j<s.size();j++) | ~^~~~~~~~~