Compilare: user.cpp: In function ‘int main()’: user.cpp:74:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (S.size() > k) ^ user.cpp: In function ‘void get_number(int&)’: user.cpp:36:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(Buffer , 1 , Bsize , stdin); ^ user.cpp:47:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(Buffer , 1 , Bsize , stdin); ^ user.cpp: In function ‘int main()’: user.cpp:55:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("peste.in","r",stdin); ^ user.cpp:56:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("peste.out","w",stdout); ^ user.cpp:58:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(Buffer , 1 , Bsize , stdin); p = 0; ^