结构推理
试根据 C++语言中运算符的优先级和结合性质，给下列表达式加上括号而不改变其求值结果∶
① a = b + c * d < 2 & 8
② a & 077 != 3
③ a == b || a == c && c < 5
④ c = x != 0
⑤ a < b == c == d
⑥ file_eof && !input_error && MIN_NUM < count && count < MAX_NUM || !error
【正确答案】① a = ((b + (c * d)) < z) & 8)
② a & (077 != 3)
③ (a == b) || (a == c) && (c < 5)
④ c = (x != 0)
⑤ ((a < b) == c) == d
⑥ (((file_eof && (! input_error)) && (MIN_NUM < count) && (count < MAX_NUM))
|| (! error))