Compilare: main.cpp: In function 'int main()': main.cpp:66:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 66 | for (i = 0; i + 1 < it->second.size(); i++) | ~~~~~~^~~~~~~~~~~~~~~~~~~ main.cpp:67:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for (j = i + 1; j < it->second.size(); j++) | ~~^~~~~~~~~~~~~~~~~~~