题目链接: 传送门

Broken Keyboard

#include<bits/stdc++.h>
using namespace std;
char str[100010];
int main()
{
    while(scanf("%s",str)!=EOF)
    {
        deque<int > q;
        int i=0;
        while(str[i]=='['||str[i]==']')  i++;
        q.push_front(i);
        while(str[i])
        {
            if(str[i]=='[')
            {
                q.push_front(i+1);
                str[i]='\0';
            }
            else if(str[i]==']')
            {
                q.push_back(i+1);
                str[i]='\0';
            }
            i++;
        }
        while(!q.empty())
        {
            printf("%s",str+q.front());
            q.pop_front();
        }
        printf("\n");

    }
    return 0;
}

刘汝佳版

// UVa11988 Broken Keyboard
// Rujia Liu
#include<cstdio>
#include<cstring>
const int maxn = 100000 + 5;
int last, cur, next[maxn]; // 光标位于cur号字符的后面
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) // 更新“最后一个字符”编号
                {
                    last = i;
                }
                cur = i; // 移动光标
            }
        }
        for(int i = next[0]; i != 0; i = next[i])
            printf("%c", s[i]);
        printf("\n");
    }
    return 0;
}