Compilare: user.cpp: In function ‘void solve(int, int, int, int)’: user.cpp:18:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[n1].size(); i++) ^ user.cpp:22:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < g[n2].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:47:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < g[i].size(); j++) ^