Compilare: user.cpp: In function ‘void solve()’: user.cpp:25:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < sir.size()){ ^ user.cpp:63:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(c < sol.size()){ ^ user.cpp:66:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < sol.size() - 1 && sol[j].first == sol[j + 1].first){ ^