Compilare: main.cpp: In constructor 'Matrix::Matrix(int, int, std::vector<std::vector<long long int> >&)': main.cpp:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for(int i = 0; i<x.size(); i++){ | ~^~~~~~~~~ main.cpp:27:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 27 | for(int j = 0; j<x[0].size(); j++){ | ~^~~~~~~~~~~~