题目链接：单链表

#include <iostream>using namespace std;const int N = 100010;int head, e[N], ne[N], idx;void init()
{head = -1;idx = 0;
}// 将x插入到头结点
void add_to_head(int x)
{e[idx] = x;ne[idx] = head;head = idx;idx++;
}// 将x插入到下标k后面
void add(int k, int x)
{e[idx] = x;ne[idx] = ne[k];ne[k] = idx;idx++;
}// 将下标是k的后面的点删掉
void remove(int k)
{ne[k] = ne[ne[k]];
}int main()
{int m;cin >> m;init();while(m--){int k, x;char op;cin >> op;if(op == 'H'){cin >> x;add_to_head(x);}else if(op == 'D'){cin >> k;if(!k) head = ne[head];remove(k - 1);}else {cin >> k >> x;add(k - 1, x);}}for(int i = head; i != -1; i = ne[i]) cout << e[i] << ' ';return 0;
}