破损的键盘（UVa 11988）

　　s[] 数组用来保存原有的字符序列

　　nex[] 数组记录打印的下标顺序

C++11 代码如下：

 #include<iostream>
 #include<cstring>
 using namespace std;
 #define maxn 100006
 char s[maxn];
 int nex[maxn], n;

 int main() {
     while (cin >> s + ) {
         int cur = , last = ;
         nex[] = ;
         char ch;
         for (int i = ; i <=strlen(s + ); i++) {
             ch = s[i];
             if (ch == '[') cur = ;
             else if (ch == ']') cur = last;
             else {
                 nex[i] = nex[cur];
                 nex[cur] = i;
                 if (cur == last)last = i;
                 cur = i;
             }
         }
         for (int i = nex[]; i != ; i = nex[i])
             cout << s[i];
         cout << endl;
     }
     return ;
 }