7.18

 

Parentheses Balance

You are given a string consisting of parentheses () and []. A string of this type is said to be correct:

(a)if it is the empty string(b)if A and B are correct, AB is correct,(c)if A is correct, (A ) and [A ] is correct.

Write a program that takes a sequence of strings of this type and check their correctness. Your program can assume that the maximum string length is 128.

Input

The file contains a positive integer n and a sequence of n strings of parentheses () and [], one string a line.

Output

A sequence of Yes or No on the output file.

Sample Input

?

1

3

?

1 2 3

([]) (([()]))) ([()[]()])()

Sample Output

?

1 2 3

Yes No Yes

 

---

2000-08-14 题意： 如果有一个'（'那么就要有一个）与它匹配，如果有一个'['那么就要有一个']'与它匹配.。如果都满足，输出”YES“，else 输出”NO“. 思路； 建立一个栈，左括号’[‘,'('都入栈，右括号')',']'都出栈依次进行下去，如果栈为空，则满足条件，输出“YES”,如果不满足条件，则输出”NO“。

源代码：点击打开链接

如果用char数组的话会报错，因为读入字符串的时候是一行读取的，题目中说有可能是空字符串，用scanf不行，用gets就会报错，所以我就用string

利用中间变元！