Compilare: main.cpp: In function 'int main()': main.cpp:79:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::set<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 79 | for(int j=0; j<v.size(); j++) | ~^~~~~~~~~ main.cpp:81:44: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 81 | if( v[j].size() >=0 && v[j].size() < k ) | ~~~~~~~~~~~~^~~ main.cpp:85:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::set<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 85 | for(i=0; i<v.size(); i++) | ~^~~~~~~~~ main.cpp:105:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::set<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 105 | for(j=0;j<v.size();j++) | ~^~~~~~~~~