Compilare: main.cpp: In function 'int main()': main.cpp:44:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::array<int, 2> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 44 | for(int h=0;h<niv.size();h++){ | ~^~~~~~~~~~~ main.cpp:48:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | for(int i=0;i<last.size();i++){ | ~^~~~~~~~~~~~ main.cpp:52:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | for(int i=0;i<niv[h].size();i++) | ~^~~~~~~~~~~~~~ main.cpp:53:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 53 | for(int j=0;j<last.size();j++) | ~^~~~~~~~~~~~ main.cpp:58:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 58 | for(int i=0;i<niv[h].size();i++) | ~^~~~~~~~~~~~~~