Eroare de compilare: user.cpp: In function ‘int read_u32()’: user.cpp:30:32: error: ‘isdigit’ was not declared in this scope while (!isdigit(c = read_ch()) && c != '-'); ^ user.cpp:37:31: error: ‘isdigit’ was not declared in this scope while (isdigit(c = read_ch())) { ^ user.cpp: In function ‘char read_ch()’: user.cpp:22:35: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(_in_buff, 1, 4096, _fin); ^ user.cpp: In function ‘int main()’: user.cpp:44:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("valoare.out", "w", stdout); ^