UVA 11988 Broken Keyboard (a.k.a. Beiju Text)(破损的键盘（又名：悲剧的文本））（链表）

Question：
Broken Keyboard (a.k.a. Beiju Text)
You’re typing a long text with a broken keyboard. Well it’s not so badly broken. The only problem with the keyboard is that sometimes the “home” key or the “end” key gets automatically pressed (internally).

You’re not aware of this issue, since you’re focusing on the text and did not even turn on the monitor! After you finished typing, you can see a text on the screen (if you turn on the monitor).

In Chinese, we can call it Beiju. Your task is to find the Beiju text.

Input
There are several test cases. Each test case is a single line containing at least one and at most 100,000 letters, underscores and two special characters ‘[’ and ‘]’. ‘[’ means the “Home” key is pressed internally, and ‘]’ means the “End” key is pressed internally. The input is terminated by end-of-file (EOF). The size of input file does not exceed 5MB.

Output
For each case, print the Beiju text on the screen.

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
Rujia Liu’s Present 3: A Data Structure Contest Celebrating the 100th Anniversary of Tsinghua University
Special Thanks: Yiming Li
Note: Please make sure to test your program with the gift I/O files before submitting!

题目大意：一个键盘出了问题，Home键和End键故障，会时不时弹出，你要把悲剧的文本找出来
解题思路：当遇到‘[]’符号时要推’[]’中的内容至屏幕最左边。可用链表，并在字符最前面添加虚拟字符，cur表示光标的位置，cur表示光标位于s[cur]的右边还需一个last表示最后一个字符
(https://www.bnuoj.com/v3/contest_show.php?cid=8307#problem/D)

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int maxn=1e5+5;char s[maxn];int next1[maxn],cur,last;int main(){    while (~scanf("%s",s+1))  //将字符串储存在是s[1],s[2]...中    {        memset(next1,0,sizeof(next1));        int len=strlen(s+1);        cur=last=0;        next1[0]=0;        for(int i=1;i<=len;i++)        {            if(s[i]=='[')  cur=0;   //当其遇到'['字符时，应输出在最前面，cur=0            else if(s[i]==']')   cur=last;  //当其遇到']'字符时，说明内容已经处理完毕，应当返回处理前的位置            else            {                next1[i]=next1[cur];  //方便储存完了特殊内容后连接原来顺序的内容，例如：next[4]是第一个特殊内容中的第一个字母next[4]=next[0]=1；这样输完了特殊内容后会按原来的顺序继续输出                next1[cur]=i;   //next[0]=4这样就会先输出第4个字母了                if(last==cur) last=i; //更新最后一个字母                cur=i; //光标移动            }        }        for(int i=next1[0];i!=0;i=next1[i])            printf("%c",s[i]);        printf("\n");    }    return 0;}