Compilare: main.cpp: In function 'int mex(std::vector<int>)': main.cpp:16:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i++) ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int h = 0; h < g[i].size(); h++) ~~^~~~~~~~~~~~~