Compilare: main.cpp: In function 'bool este_valid(int, std::vector<int>&)': main.cpp:13:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(int lineOld = 0; lineOld < curent.size(); lineOld++) | ~~~~~~~~^~~~~~~~~~~~~~~ main.cpp: In function 'void backtrack(std::vector<std::vector<int> >&, std::vector<int>&, int)': main.cpp:24:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 24 | if(curent.size() == n) | ~~~~~~~~~~~~~~^~~~