Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:12:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:85:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<vcc[i].size();j++) ^ user.cpp:60:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.in","r",stdin); ^ user.cpp:61:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.out","w",stdout); ^ user.cpp:62:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:65:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^