Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:27:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v.size(); i+=2) ^ user.cpp: In function ‘int main()’: user.cpp:36:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("drumuri.in","r",stdin); ^ user.cpp:37:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("drumuri.out","w",stdout); ^ user.cpp:38:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:48:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^