C++学习———数据结构

链表。

#include <iostream>
using namespace std;

class myLinkedList{
    
    
private:
    int _size;
    LinkedNode* _dummyHead;
public:
    struct LinkedNode {
    
    
        int val;
        LinkedNode* next;
        LinkedNode(int val) : val(val), next(nullptr) {
    
    }
    };

    //初始化链表
    myLinkedList() {
    
    
        _dummyHead = new LinkedNode(0);
        _size = 0;
    }

    //获取 index 的值
    int get(int index) {
    
    
        if (index < 0 || index > _size-1) {
    
    
            return -1;
        }
        LinkedNode* cur = _dummyHead->next;
        while (index--) {
    
    
            cur = cur->next;
        }
        return cur->val;
    }

    //在链表最前面插入一个节点
    void addAthead(int val) {
    
    
        LinkedNode* newNode = new LinkedNode(val);
        newNode->next = _dummyHead->next;
        _dummyHead->next = newNode;
        _size++;
    }

    //在链表最后面添加一个节点
    void addAtTail(int val) {
    
    
        LinkedNode* cur = _dummyHead;
        while (cur->next != nullptr) {
    
    
            cur = cur->next;
        }
        LinkedNode* newNode = new LinkedNode(val);
        cur->next = newNode;
        _size++;
    }

    //在index节点之前插入节点
    void addAtindex(int index, int val) {
    
    
        if (index < 0 || index > _size) {
    
    
            return ;
        }
        LinkedNode* newNode = new LinkedNode(val);
        LinkedNode* cur = _dummyHead;
        while (index--) {
    
    
            cur = cur->next;
        }
        newNode->next = cur->next;
        cur->next = newNode;
        _size++;
    }

    //删除index节点
    void delIndex(int index) {
    
    
        if (index < 0 || index > _size-1) {
    
    
            return;
        }

        LinkedNode* cur = _dummyHead;
        while (index--) {
    
    
            cur = cur->next;
        }
        LinkedNode* delNode = cur->next;
        cur->next = delNode->next;
        delete delNode;
        _size--;
    }

    //输出链表
    void printList() {
    
    
        LinkedNode* cur = _dummyHead;
        while (cur->next != nullptr) {
    
    
            cout << cur->next->val << endl;
            cur = cur->next;
        }
    }
};