Compilare: main.cpp: In function 'int check(int, int)': main.cpp:19:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | for(int i = 1; i<v[x].size(); i++) | ~^~~~~~~~~~~~ main.cpp:21:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for(int j = 1; j<v[y].size(); j++) | ~^~~~~~~~~~~~