Compilare: main.cpp: In function 'void megold(std::vector<std::vector<int> >&, std::vector<int>, int)': main.cpp:31:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | while (j < a.size() && x<=a[j][a[j].size()-1]) | ~~^~~~~~~~~~ main.cpp:35:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | if (j == a.size()) | ~~^~~~~~~~~~~