Compilare: user.cpp: In function ‘int main()’: user.cpp:71:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(lung<V[0].size() && lung<V[1].size() && V[0][lung].first==V[1][lung].first) ~~~~^~~~~~~~~~~~ user.cpp:71:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(lung<V[0].size() && lung<V[1].size() && V[0][lung].first==V[1][lung].first) ~~~~^~~~~~~~~~~~ user.cpp:74:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=lung; i<V[0].size(); i++) ~^~~~~~~~~~~~ user.cpp:76:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=lung; i<V[1].size(); i++) ~^~~~~~~~~~~~ user.cpp:78:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lung==V[0].size()) ~~~~^~~~~~~~~~~~~ user.cpp:84:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lung==V[1].size()) ~~~~^~~~~~~~~~~~~