Eroare de compilare: user.cpp: In function ‘char next()’: user.cpp:9:28: error: ‘fin’ was not declared in this scope fread(buf, 1, BUF, fin), pos = 0; ^~~ user.cpp: In function ‘int get_int()’: user.cpp:16:22: error: ‘isdigit’ was not declared in this scope while(!isdigit(ch) && ch != '-') ^ user.cpp:20:21: error: ‘isdigit’ was not declared in this scope while(isdigit(ch)) ^ user.cpp: In function ‘int main()’: user.cpp:34:11: error: ‘buffer’ was not declared in this scope fread(buffer, 1, 45000000, stdin); ^~~~~~ user.cpp:31:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("deque.in", "r", stdin); ^