手写链表实现

末蓝、 2023-10-08 14:59 9阅读 0赞

增删改查写腻了嘛  
跟我一起手写链表的实现吧

仅为学习用，所以这里数据域只存int类型的数据了

public class LinkList {
        
        public static void main(String[] args) {
        
            int[] a = {
        1, 2, 3, 4, 5, 6};
            Node head = initLinkedList(a);
            System.out.println("初始化成功");
            System.out.println("获取长度："+getLength(head));
            System.out.println("转为字符串输出："+toString(head));
            head = insertNode(head,new Node(0),1);
            System.out.println("头插："+toString(head));
            head = insertNode(head,new Node(7),7);
            System.out.println("尾插："+toString(head));
            head = deleteNode(head,1);
            System.out.println("头删："+toString(head));
            head = deleteNode(head,6);
            System.out.println("尾删："+toString(head));
        }
    
        /**
         * 插入节点
         * @param head 头结点
         * @param insertNode 待插入结点
         * @param position 插入位置
         * @return 插入后的链表头结点
         */
        public static Node insertNode(Node head,Node insertNode,int position){
        
            //判空
            if(head==null){
        
                return insertNode;
            }
            //判断是否越界
            int size = getLength(head);
            if(position>size+1||position<1){
        
                System.out.println("越界异常");
                return head;
            }
            //头插
            if(position==1){
        
                insertNode.next = head;
                head = insertNode;
                return head;
            }
            //中间及尾插
            Node midNode = head;
            int count = 0;
            while (count < position-1){
        
                midNode = midNode.next;
                count++;
            }
            insertNode.next = midNode.next;
            midNode.next = insertNode;
            return head;
        }
    
        /**
         * 删除结点
         * @param head 头结点
         * @param position 删除的位置
         * @return 输出的链表
         */
        public static Node deleteNode(Node head,int position){
        
            //判空
            if(head==null){
        
                System.out.println("链表为空，无法删除");
                return null;
            }
            //判断参数是否越界
            int size = getLength(head);
            if(position>size||position<=0){
        
                System.out.println("位置参数输入有误");
                return head;
            }
            if(position==1){
        
                return head.next;
            }
            Node midNode = head;
            int count = 1;
            while (count<position){
        
                count++;
                midNode = midNode.next;
            }
            midNode.next = midNode.next.next;
            return  head;
        }
        /**
         * 输出链表
         * @param head 头结点
         * @return 输出的链表
         */
        public static String toString(Node head){
        
            Node node = head;
            StringBuilder str = new StringBuilder();
            while (node!=null){
        
                str.append(node.val).append(" ");
                node = node.next;
            }
            return str.toString();
        }
        /**
         * 获取链表长度
         * @param head 头结点
         * @return 链表长度
         */
        public static int getLength(Node head){
        
            int length = 0;
            Node node = head;
            while (node!=null){
        
                length++;
                node = node.next;
            }
            return length;
        }
        /**
         * 链表初始化
         * @param array
         * @return
         */
        public static Node initLinkedList(int[] array){
        
            Node head = null,cur = null;
            for (int i = 0; i < array.length; i++) {
        
                Node newNode = new Node(array[i]);
                if(i==0){
        
                    head = newNode;
                    cur = head;
                }else {
        
                    cur.next = newNode;
                    cur = newNode;
                }
            }
            return head;
        }
        static class Node{
        
            public int val;
            public Node next;
    
            Node(int x) {
        
                val = x;
                next = null;
            }
        }
    }