算法1 动态链表

C++ 代码

#include<iostream>
#include<vector>
using namespace std;
struct Node
{
    int val;
    Node* next;
    Node(int x) : val(x), next(nullptr) {}
};
class Mylist {
public:
    Mylist() : head(nullptr), v() {}
public:
    void addhead(int x) {
        Node* u = new Node(x);
        u->next = head;
        head = u;
        v.push_back(u);
    }
    void deleteh(int k) {
        if (k == 0) head = head->next;
        else {
            Node* r = v[k - 1];
            Node* pre = v[k - 1]->next;
            if (pre->next && pre) r->next = pre->next;
            else r->next = nullptr;
        }
    }
    void assertafter(int k, int j) {
        Node* newnode = new Node(j);
        v.push_back(newnode);
        newnode->next = v[k-1]->next;
        v[k-1]->next = newnode;


    }
    void printList() {
        Node* current = head;
        while (current) {
            cout << current->val << " ";
            current = current->next;
        }
        cout << endl;
    }

private:
    Node* head;
    vector <Node*> v;
};
int main() {
    int num, a, b;
    char c;
    cin >> num;
    Mylist mylist;
    for (int i = 0; i < num; i++) {
        cin >> c;
        if (c == 'H') {
            cin >> a;
            mylist.addhead(a);
        }
        if (c == 'D') {
            cin >> a;
            mylist.deleteh(a);
        }
        if (c == 'I') {
            cin >> a >> b;
            mylist.assertafter(a, b);
        }
    }
    mylist.printList();
    return 0;
}