Compilare: main.cpp:13:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^ main.cpp: In function 'int main()': main.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < aux.size(); ++i) ~~^~~~~~~~~~~~ main.cpp:42:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < aux.size() && aux[j].first == aux[i].first) ~~^~~~~~~~~~~~