C++ 代码

1.数组模拟链表，速度很快
2.用scanf printf不用cin cout 会很快（59ms）
3.注意scanf循环读取单个字符：scanf(" %c", &op)

# include <iostream>
# include <stdio.h>
using namespace std;
const int N = 100010;

int e[N], ne[N], head, idx;

void init()
{
    head = -1, idx = 0;
}

void add_to_head(int x)
{
    e[idx] = x, ne[idx] = head, head = idx ++;
}

void add(int k, int x)
{
    e[idx] = x, ne[idx] = ne[k], ne[k] = idx ++;
}

void remove(int k)
{
    ne[k] = ne[ne[k]];
}

int main()
{
    int m;
    scanf("%d", &m);
    init();
    while(m --)
    {
        char op;
        int x, k;
        scanf(" %c", &op); // 注意这里" %c"
        //cin >> op;
        if(op == 'H')
        {
            scanf("%d", &x);
            add_to_head(x);   
        }
        else if(op == 'I')
        {
            scanf("%d%d", &k,&x);
            add(k - 1, x);

        }
        else if(op == 'D')
        {
            scanf("%d", &k);
            if(!k) head = ne[head];
            remove(k - 1);
        }
    }
    for (int i = head; i != -1; i = ne[i]) printf("%d ", e[i]);
    return 0;
}