NYoj 2 括号配对问题

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

const int MAXN = 10010;

int main()
{
char str[MAXN];
int top, T, Len, i;
scanf("%d", &T);
while(T--)
{
scanf("%s", str);
Len = strlen(str);
if(Len % 2)
{
printf("No\n");
continue ;
}
top = 0;
for(i = 1; i < Len; ++i)
{
if((str[top] == '(' && str[i] == ')') || (str[top] == '[' && str[i] == ']'))
--top;
else
str[++top] = str[i];
}
if(top == -1)
printf("Yes\n");
else
printf("No\n");
}
return 0;
}