skiplist

public class SkipList {
    class Node{
        int value = -1;
        int level;
        //这里用的数组
        Node[] next;

        public Node(int value, int level) {
            this.value = value;
            this.level = level;
            next = new Node[level];
        }
    }
    //参数分别为 最大层数，dumn头节点，节点的个数，层数
    int maxValue = 16;
    Node head = new Node(-1,16);
    int size = 0;
    int levelCount = 1;

    //很明显 每一层里面使用next（这里固定住了i） 而每一层之间使用下标(也就是i)
    //这里node直接使用了数组 可以理解成全局只有一个next对象？
    //next[0]表示什么？
    public Node find(int value){
        Node temp = head;
        //i代表横着走 由于node结构本来就是 node【】 所有从上一定可以往下
        for (int i = levelCount-1; i >= 0 ; i--) {
            while(temp.next[i] != null && temp.value < value){
                temp = temp.next[i];
                System.out.println(temp.value+" "+i);
            }
        }
        if(temp.next[0] != null && temp.next[0].value == value){
            System.out.println("查找成功");
            return temp.next[0];
        }else{
            System.out.println("查无此数");
            return null;
        }
    }
    public void insert(int value){
        int level = getLevel();
        Node newNode = new Node(value, level);
        Node[] update = new Node[level];

        Node temp = head;
        for (int i = level-1; i >= 0 ; i--) {
            while(temp.next[i] != null && temp.next[i].value < value){
                //永远都是需要一个数组的
                temp = temp.next[i];
            }
            update[i] = temp;
        }
        for (int i = 0; i < level; i++) {
            newNode.next[i] = update[i].next[i];
            update[i].next[i] = newNode;
        }
        if(level > levelCount){
            levelCount = level;
        }
        size++;
        System.out.println(value+"插入成功");
    }
    public void del(int value){
        Node[] update = new Node[levelCount];
        Node temp = this.head;
        for (int i = levelCount-1; i >= 0 ; i--) {
            while (temp.next[i] != null && temp.next[i].value < value){
                temp = temp.next[i];
            }
            update[i] = temp;
        }
        if(temp.next[0]!=null && temp.next[0].value == value){
            size -- ;
            System.out.println(value + "删除成功");
            for (int i = levelCount-1; i >= 0 ; i--) {
                if(update[i].next[i] != null && update[i].next[i].value == value){
                   update[i].next[i] = update[i].next[i].next[i];
                }
            }
        }
    }
    private int getLevel() {
        int level = 1;
        while (true){
            int t = (int)(Math.random()*100);
            if(t%2 == 0){
                level++;
            }else{
                break;
            }
        }
        System.out.println("当前level为"+level);
        return level;
    }
    public void printAll(){
        Node temp = head;
        //直接输出最底下那层
        while(temp.next[0] != null){
            System.out.println(temp.next[0].value+"  ");
            temp = temp.next[0];
        }
    }

    public static void main(String[] args) {
        SkipList skipList = new SkipList();
        for (int i = 0; i < 2; i++) {
            skipList.insert(i);
        }
        skipList.printAll();
        skipList.del(3);
        skipList.printAll();
        System.out.println("************************************************");
        System.out.println(skipList.find(3));
    }

}