Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:14:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) dfs(v[nod][i]); ^ user.cpp:18:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[nod].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:29:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("iepuri2.in","r",stdin); ^ user.cpp:30:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("iepuri2.out","w",stdout); ^ user.cpp:32:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k1); ^ user.cpp:35:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp:31:15: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n,x,y,nod; ^