Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:26:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[node].size(); i++){ ^ user.cpp: In function ‘int main()’: user.cpp:58:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biperm.in", "r", stdin); ^ user.cpp:59:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biperm.out", "w", stdout); ^ user.cpp:62:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:65:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &P[i][j]); ^