Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:24:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<g[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:54:40: 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:55:42: 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:56:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&t); euler[1]=1; ^ user.cpp:59:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:66:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&p,&r); ^