Compilare: user.cpp: In function ‘int main()’: user.cpp:33:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("blis.in","r",stdin); ^ user.cpp:34:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("blis.out","w",stdout); ^ user.cpp:35:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%s", &K, (s + 1) ) ; ^