单链表
ne即next指针数组,e即存储的数值,idx当前未分配的数组下标,head为头节点指向的数组下标
#include<bits/stdc++.h>
using namespace std;
const int M = 100010;
int ne[M], e[M], idx, head;
void init()
{
idx = 0;
head = -1;
}
void add_from_head(int x)
{
e[idx] = x;
ne[idx] = head;
head = idx;
idx++;
}
void add(int k, int x)
{
e[idx] = x;
ne[idx] = ne[k];
ne[k] = idx;
idx++;
}
void remove(int k)
{
ne[k] = ne[ne[k]];
}
int main()
{
int m, x, k;
scanf("%d", &m);
init();
while(m--)
{
char op;
cin >> op;
if(op == 'H')
{
scanf("%d", &x);
add_from_head(x);
}
else if(op == 'D')
{
scanf("%d", &k);
if(k == 0)
head = ne[head];
else remove(k - 1);
}
else if(op == 'I')
{
scanf("%d %d", &k, &x);
add(k - 1, x);
}
}
for(int i = head; i != -1; i = ne