Compilare: user.cpp: In function ‘int pairup(int)’: user.cpp:19:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i<G[nod].size();i++) ^ user.cpp:27:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i<G[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:41:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("revolutie.in","r",stdin); ^ user.cpp:42:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("revolutie.out","w",stdout); ^ user.cpp:43:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:47:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a); ^