题目描述

blablabla

样例

#define _CRT_SECURE_NO_DEPRECATE
#include<iostream>
using namespace std;
const int N = 1e5 + 10;
int ne[N], e[N], idx = 1, head = 0;
void addHead(int x)
{
    e[idx] = x;
    ne[idx] = head;
    head = idx++;
}
void insert(int k, int x)
{
    e[idx] = x;
    ne[idx] = ne[k];
    ne[k] = idx++;
}
void delTail(int x)
{
    ne[x] = ne[ne[x]];
}
int main()
{
    int M;
    scanf("%d", &M);
    while (M--)
    {
        char op[2];
        scanf("%s", &op);
        int m, n;
        switch (op[0])
        {
        case 'H':
            scanf("%d", &m);
            addHead(m);
            break;
        case 'I':
            scanf("%d%d", &m, &n);
            insert(m, n);
            break;
        case 'D':
            scanf("%d", &m);
            if (m)  delTail(m);
            else head = ne[head];
            break;
        default:
            break;
        }
    }
    int cur = head;
    while (cur) printf("%d ", e[cur]), cur = ne[cur];
    return 0;
}

算法1

(暴力枚举) $O(n^2)$

blablabla

时间复杂度

参考文献

C++ 代码

blablabla

算法2

(暴力枚举) $O(n^2)$

blablabla

时间复杂度

参考文献

C++ 代码

blablabla