正文之前

重温算法，今天看了下《算法导论》，二叉搜索树的内容，总算没有以前看的时候的那种晦涩感了。。。明天继续加油！！！今天大概用Java实现了下二叉搜索树的建立和输出，至于检索这个简单功能就不说了，插入功能也实现了。就差个删除了~emmm 明天上午搞完它！！！

这个是Java的《数据结构》

要电子书的可以找我。。。留下邮箱即可。。

正文

import java.util.Arrays;
import java.util.Random;
import java.util.LinkedList;
import java.util.Queue;

class node{
    private int key;
    node leftChild;
    node rightChild;
    node parent;
    node(int x){
        this.key=x;
    }
    node(){};
    public node getLeftChild(){
        return this.leftChild;
    }
    public node getRightChild(){
        return this.rightChild;
    }
    public int getKey(){
        return this.key;
    }
    public node getParent(){
        return this.parent;
    }
}

class Tree{
    node head;
    int size;
    Tree(){this.size = 0;};
    public node getHead(){
        return this.head;
    }
    public void walk(Queue<String> queue,node par){
        if(par.getLeftChild()!=null){
            queue.add("* "+par.getLeftChild().getKey()+ " ");
            walk(queue,par.getLeftChild());
        }
        if (par.getRightChild()!=null){
            queue.add("* "+par.getRightChild().getKey() + " ");
            walk(queue,par.getRightChild());
        }
    }
    public String toString(){
        System.out.print("输出树形: ");
        Queue<String> queue = new LinkedList<>();
        String out = "";
        if (this.head!=null){
            String one = "ok";
            walk(queue,this.head);
            while(one!=null) {
                one = queue.poll();
                if(one!=null)
                    out += one;
            }
            queue.add("* "+this.head.getKey()+"\n");

        }
        return out;
    }
}

public class TestTree{
    public static void insertSort(int []arr, int n){
        for (int i = 1; i < n; ++i)
        {
            int e = arr[i];
            int j=i;
            for (; j > 0; --j)
            {
                if (e < arr[j-1])
                    arr[j] = arr[j-1];
                else
                    break;
            }
            arr[j] = e;
        }
    }
    public static void insertToTree(Tree tree,int x){
        tree.size+=1;
        node newnode = new node(x);
        node tmp = tree.getHead();
        if ( tmp==null)
            tree.head = newnode;
        while(tmp!=null) {
            if (x < tmp.getKey()) {
                if (tmp.getLeftChild()==null || x > tmp.getLeftChild().getKey()) {
                    newnode.parent = tmp;
                    newnode.leftChild = tmp.getLeftChild();
                    tmp.leftChild = newnode;
                    return;
                }
                else
                    tmp = tmp.getLeftChild();
            }
            else {
                if ( tmp.getRightChild()==null || x > tmp.getRightChild().getKey()) {
                    newnode.parent = tmp;
                    newnode.rightChild = tmp.getRightChild();
                    tmp.rightChild = newnode;
                    return;
                }
                else
                    tmp = tmp.getRightChild();
            }
        }
    }
    public static Tree generateTree(int[] arr){
        Tree tree = new Tree();
//        insertSort(arr,arr.length);
        int head = arr.length/2;
        insertToTree(tree,arr[head]);
        for (int i=0;i<arr.length;++i) {
            if (i!=head) {
                insertToTree(tree,arr[i]);
            }
        }
        return tree;
    }
    public static void main(String[] args) {
        Random rdm = new Random(System.currentTimeMillis());
        int [] randomArr = new int[20];
        for(int i=0;i<20;i++)
            randomArr[i] = Math.abs(rdm.nextInt())%50 +1;
        Tree tree = generateTree(randomArr);
        System.out.println(Arrays.toString(randomArr));
        System.out.println(tree.toString());
    }
}

正文之后

溜了溜了~~~回去玩手机去！