Compilare: main.cpp: In function 'int main()': main.cpp:62:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[x].size();j++) if(v[x][j].second==y) {ok=0;mx=v[x][j].first;} ~^~~~~~~~~~~~ main.cpp:66:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[x].size();j++) ~^~~~~~~~~~~~ main.cpp:71:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[y].size();j++) ~^~~~~~~~~~~~