Compilare: main.cpp: In function 'int main()': main.cpp:60:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::unordered_map<int, std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | for (i = 1; i <= sol.size(); i++) | ~~^~~~~~~~~~~~~ main.cpp:63:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 63 | for (j = 0; j < sol[i].size(); j++) | ~~^~~~~~~~~~~~~~~