Compilare: main.cpp: In function 'int main()': main.cpp:16:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[n2].size();i++) ~^~~~~~~~~~~~~ main.cpp:26:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[n2].size();i++) ~^~~~~~~~~~~~~ main.cpp:34:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[n2].size();i++){ ~^~~~~~~~~~~~~