uva11988 - Broken Keyboard (a.k.a. Beiju Text) 入门经典II 第六章数据结构基础 例题6-4

题目链接：http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=229&page=show_problem&problem=3139

Sample Input

This_is_a_[Beiju]_text
[[]][][]Happy_Birthday_to_Tsinghua_University

Output for the Sample Input

BeijuThis_is_a__text
Happy_Birthday_to_Tsinghua_University

汝佳提供的代码并没有理解透彻，下面是汝佳的代码：

// UVa11988 Broken Keyboard
// Rujia Liu
#include<cstdio>
#include<cstring>
const int maxn = 100000 + 5;
int last, cur, next[maxn]; // 光标位于cur号字符之后面
char s[maxn];

int main() {
  while(scanf("%s", s+1) == 1) {
    int n = strlen(s+1); // 输入保存在s[1], s[2]...中
    last = cur = 0;
    next[0] = 0;

    for(int i = 1; i <= n; i++) {
      char ch = s[i];
      if(ch == '[') cur = 0;
      else if(ch == ']') cur = last;
      else {
        next[i] = next[cur];
        next[cur] = i;
        if(cur == last) last = i; // 更新“最后一个字符”编号
        cur = i; // 移动光标
      }
    }
    for(int i = next[0]; i != 0; i = next[i])
      printf("%c", s[i]);
    printf("\n");
  }
  return 0;
}