Compilare: main.cpp: In function 'bool verif(std::vector<int>&, int, int)': main.cpp:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < b.size(); ++i) { ~~^~~~~~~~~~ main.cpp:29:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < a[el_curent].size(); ++j) { ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:81:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < s.size(); ++j) { ~~^~~~~~~~~~