uva 673 Parentheses Balance（栈）

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 

 

3
([])
(([()])))
([()[]()])()

 

Sample Output 

Yes
No
Yes

题目大意：确定括号是否匹配。
注意：空语句输出Yes

解题思路：左括号入栈，右括号匹配出栈。

#include<string.h>
#include<stack>
#include<cstdio>
using namespace std;

#define N 200

int main()
{
int n;

char str
;
int bo;

scanf("%d", &n);
getchar();

while(n--)
{
// Init.
memset(str, 0, sizeof(str));
bo = 1;
stack<char> q;

// Read.
gets(str);
int m = strlen(str);
for(int i = 0; i < m ; i++)
{
if(str[i] == '(' || str[i] == '[')
q.push(str[i]);
else if(str[i] == ')')
{
if(q.empty() || q.top() != '(')
{
bo = 0;
break;
}
else
q.pop();
}
else if(str[i] == ']')
{
if(q.empty() || q.top() != '[')
{
bo = 0;
break;
}
else
q.pop();
}
}

if(bo && q.empty())
printf("Yes\n");
else
printf("No\n");
}
return 0;}