Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:9:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int co=0;co<v[nod].size();co++) ^ user.cpp: In function ‘void dfs1(int)’: user.cpp:19:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int co=0;co<v1[nod].size();co++) ^ user.cpp: In function ‘int main()’: user.cpp:52:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<r[i].size();j++) ^ user.cpp:25:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:26:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp:27:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:31:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^