Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:34:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int it = 0; it < L[node].size(); ++it) { ^ user.cpp: In function ‘int main()’: user.cpp:85:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int it = 0; it < L[node].size(); ++it) { ^ user.cpp:97:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int itt = 0; itt < parents[child].size(); ++itt) { ^