Compilare: user.cpp: In function ‘int main()’: user.cpp:26:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pq.size()>=K) ^ user.cpp:15:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sirag.in","r",stdin); ^ user.cpp:16:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sirag.out","w",stdout); ^ user.cpp:18:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&K); ^ user.cpp:22:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&c); ^