Compilare: main.cpp: In function 'int main()': main.cpp:31:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[a].size(); i++) { ~~^~~~~~~~~~~~~ main.cpp:37:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l.size(); i++) { ~~^~~~~~~~~~