Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:19:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int it = 0; it < v[nod].size(); ++it) ^ user.cpp: In function ‘void citire()’: user.cpp:30:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in", "r", stdin); ^ user.cpp:31:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:34:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp: In function ‘void query()’: user.cpp:75:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lca.out", "w",stdout); ^ user.cpp:78:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^