题目：http://acm.nyist.edu.cn/JudgeOnline/problem.php?pid=2
被strlen()坑了（自己太菜> <），许久没用它，写的时候：l = strlen(br) - 1;。。。。但纠正以后还是WA了，我觉得自己代码没啥毛病（就当AC了吧。。）：
#include <iostream>
#include <string.h> // oj上不加这个会CE
using namespace std;
#define M 10001
int main()
{
char br[M], s[M]; int t, l, i, flag;
cin >> t;
while (t--)
{
cin >> br;
l = strlen(br);
flag = i = 0;
if (br[l] == '(' || br[l] == '[' || l == 1)
cout << "No" << endl;
else {
while (l > -1)
{
switch (br[l])
{
case ')': s[i++] = br[l]; break;
case ']': s[i++] = br[l]; break;
case '(': switch (s[i - 1])
{
case ')': i--; break;
default: flag = 1; break;
}
break;
case '[': switch (s[i - 1])
{
case ']': i--; break;
default: flag = 1; break;
}
break;
}
if (flag)
break;
l--;
}
if (flag)
cout << "No" << endl;
else
cout << "Yes" << endl;
}
}
return 0;
}