Compilare: user.cpp: In function ‘int main()’: user.cpp:41:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bleach.in","r",stdin); ^ user.cpp:42:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bleach.out","w",stdout); ^ user.cpp:43:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); k=2*k+3; if (2*k+3>n) k=n; ^ user.cpp:44:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=k-1;i++) scanf("%d", &a[i]); ^ user.cpp:47:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[k]); heap_up(k); ^