Compilare: main.cpp: In function 'int main()': main.cpp:67:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for(int i=0;i<ans.size();i++) | ~^~~~~~~~~~~ main.cpp:69:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 69 | for(int j=0;j<ans[i].size();j++) | ~^~~~~~~~~~~~~~