Compilare: main.cpp:14:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^ main.cpp: In function 'int main()': main.cpp:53:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(it1 < vec[i].size() && vec[i][it1].first <= act + 1) ~~~~^~~~~~~~~~~~~~~ main.cpp:56:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(it2 < vec[j].size() && vec[j][it2].first <= act + 1) ~~~~^~~~~~~~~~~~~~~