数据结构_单链表操作总结1

package zz;

import java.util.Stack;

import zz.LinkedListSummary.Node;

/**
 * 参考博客：http://blog.csdn.net/lavor_zl/article/details/42803431
 * @author zz
 * 关于java中链表的操作
 * 0. 删除带头结点的单链表的节点p,p不是尾节点，并且要求时间复杂度为O(1)
 * 1. 删除带头结点的单链表的节点p,p可能为尾节点，也可能是任意其他节点
 */
public class LinkedListSummary2 {
    public static class Node {
        int data;
        Node next;
        public Node(int value) {
            data = value;
        }
    }
    //向链表中插入新节点
    public static Node addNode(Node head, int data) {
        Node newNode = new Node(data);
        if(head == null) {
            head = newNode;
        } 
        Node temp = head;
        while(temp.next != null) {
            temp = temp.next;
        }
        temp.next = newNode;
        return newNode;
        
    }
    //顺序打印链表数据 
    public static void print(Node head) {
        if(head == null) {
            System.out.println("链表为空");
            return;
        } else {
            Node temp = head;
            while(temp != null) {
                System.out.print(temp.data + " ");
                temp = temp.next;
            }
        }
    }
    //删除带头结点的单链表的节点p,p不是尾节点，并且要求时间复杂度为O(1)
    public static void deleteNode(Node p) {
        if(p == null || p.next == null) return;
        Node q = p.next;
        p.data = q.data;
        p.next = q.next;
    }
    //删除带头结点的单链表的节点p,p可能为尾节点，也可能是任意其他节点
    public static void deleteNode(Node head, Node p) {
        if(head == null || p == null) return;
        Node temp = null;
        if(p.next != null) {   //p不是尾节点
            Node n = p.next;
            p.data = n.data;
            p.next = n.next;
        } else {   //p是尾节点
            Node node = head;
            while(node.next != null) {
                temp = node;
                node = node.next;
            }
            temp.next = null;
        }
    }
    
    public static void main(String[] args) {
        Node head = new Node(0);
        Node h1 = addNode(head, 1);
        Node h2 = addNode(head, 2);
        Node h3 = addNode(head, 3);
        Node h4 = addNode(head, 4);
        Node h5 = addNode(head, 5);
        System.out.println("顺序打印单链表:");
        print(head);
        System.out.println();
        System.out.println("删除链表头结点:");
        deleteNode(head, h5);
        print(head);
        System.out.println();
        
    }
}