Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘void dfs1(int)’: user.cpp:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vt[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:30:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tarnacop.in","r",stdin); ^ user.cpp:31:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tarnacop.out","w",stdout); ^ user.cpp:33:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&S,&D); ^ user.cpp:36:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&x,&y,&c,&f); ^