public class ListNode {
public int value;
public ListNode next;
public ListNode(int value) {
this.value = value;
}
}
public class Mylist {
/**
* 头结点插入
*/
public static void headInsert(ListNode head, ListNode newHead) {
ListNode old = head;
head = newHead;
head.next = old;
}
/**
* 尾节点插入
*/
public static void tailInsert(ListNode tail, ListNode newTail) {
ListNode old = tail;
tail = newTail;
old.next = tail;
newTail.next = null;
}
/**
* 遍历
*/
public static void traverse(ListNode head) {
while(head != null) {
System.out.print(head.value+" ");
head = head.next;
}
System.out.println();
}
/**
* 查找
*/
public static int find(ListNode head, int value) {
int index = -1;
int count = 0;
while(head != null) {
if(head.value == value) {
index = count;
return count;
}
count++;
head = head.next;
}
return index;
}
/**
* 中间插入
* @param oldNode
* @param newNode
*/
public static void insert(ListNode p, ListNode s) {
ListNode next = p.next;
p.next = s;
s.next = next;
}
/**
* 删除节点
*/
public static void delete(ListNode head, ListNode q) {
if(q != null) {
if(q.next != null) {
ListNode p = q.next;
q.value = p.value;
q.next = p.next;
p = null;
}else {//删除最后一个元素的情况
while(head != null) {
if(head.next != null && head.next == q) {
head.next = null;
break;
}
head = head.next;
}
}
}
}
public static void main(String[] args) {
ListNode node1 = new ListNode(1);
ListNode node2 = new ListNode(2);
ListNode node3 = new ListNode(3);
node1.next = node2;
node2.next = node3;
node3.next = null;
traverse(node1);
//头结点插入
ListNode newHead = new ListNode(0);
headInsert(node1, newHead);
traverse(newHead);
//尾节点插入
ListNode newTail = new ListNode(4);
tailInsert(node3, newTail);
traverse(newHead);
//中间节点插入
ListNode node = new ListNode(5);
insert(node2, node);
traverse(newHead);
//删除非尾节点
delete(node1, node);
traverse(newHead);
//删除尾节点
delete(newHead, newTail);
traverse(newHead);
}
}
