Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:28:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<lcrt[nd].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:69:17: warning: unused variable ‘kk’ [-Wunused-variable] int kk=1; ^ user.cpp:36:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ user.cpp:37:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^ user.cpp:39:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d",&n,&m); ^ user.cpp:43:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d",&x,&y,&cst); ^