【求助】关于栈的。。

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 3 ([]) (([()]))) ([()[]()])() Sample Output Yes No Yes

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 

下面是我的代码。帮忙看一下哪里有问题
#include<stdio.h>
#include<iostream>
#include<stack>
#include<string.h>
using namespace std;
int main()
{
char str[200];
int mark,n,len,i;
scanf("%d",&n);
cin.get();
while (n--)
{
stack <int> s;
gets(str);
len=strlen(str);
s.push(1);
for(i=0; i<len; i++)
{
if(str[i]=='('||str[i]=='[')
s.push(str[i]);
if(str[i]==')')
{
if(s.top()=='(')
{
s.pop();
continue;
}
else
{
printf("no\n");
break;
}
}
else if(str[i]==']')
{
if(s.top()=='[')
{
s.pop();
continue;
}
else
{
printf("no\n");
break;
}
}
}
if(i==len)
{
s.pop();
if(s.empty()) printf("yes\n");
else printf("no\n");
}
}
return 0;
}

来人额

@飞翔的天地
@ 关签
@ 御坂美琴みさか
来人额。。

@飞翔的天地
@关签
@御坂美琴みさか 

？？？

楼主程序没错，但犯个弱智错误，检查输出和题目要求的一样不？注意大小写