Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:18:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < Q[nod].size(); i += 2){ ^ user.cpp:26:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < V[nod].size(); i ++){ ^ user.cpp: In function ‘int main()’: user.cpp:37:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stramosi.in" ,"r", stdin ); ^ user.cpp:38:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stramosi.out","w", stdout); ^ user.cpp:40:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:44:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &X); ^ user.cpp:50:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &X, &Y); ^