Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:60:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:72:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harbingers.in","r",stdin); ^ user.cpp:73:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harbingers.out","w",stdout); ^ user.cpp:75:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:78:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^ user.cpp:82:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=2;i<=n;i++) scanf("%d%d",&s[i],&v[i]); ^