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;
}
}
};