排序 没事练习

package com.taotao.api;

import org.junit.Test;

import java.util.Arrays;
import java.util.List;

public class SortTest2 {


    @Test
    public void sortInsert() {

        int[] array = new int[5];

        array[0] = 2;
        array[1] = 1;
        array[2] = 4;
        array[3] = 5;
        array[4] = 1;

        for (int i = 0; i < array.length; i++) {
            //查找合适位置
            int point = i;
            for (int j = 0; j < i; j++) {
                if (array[i] < array[j]) {
                    point = j;
                    break;
                }
            }
            if (i == point) continue;

            int temp = array[i];
            //序列后移
            for (int j = i; j > point; j--) {
                array[j] = array[j - 1];
            }
            //赋值合适位置
            array[point] = temp;
        }

        for (int i : array) {
            System.out.print(i);
        }

    }

    @Test
    public void sortQuick() {
        List<Integer> arrayList = Arrays.asList(15,17,2,4,3);
        int[] list = arrayList.stream().mapToInt(x -> x).toArray();
        quick(list, 0, list.length - 1);
    }

    private void quick(int[] list, int left, int right) {

        int head = left;
        int tail = right;

        //以temp 作为对比值
        Integer temp = list[head];
        while (head < tail) {
            //从后往前 找最近一个小于 对比值
            //并将 此值 扔到 head位置
            while (head < tail && list[tail] >= temp) tail--;
            if (head != tail) {
                list[head] = list[tail];
            }
            //从前往后 找大于对比值的
            //扔到 tail 位置
            while (head < tail && list[head] <= temp) head++;
            if (head != tail) {
                list[tail] = list[head];
            }
        }
        //将对比值 扔到 合适位置
        if (head == tail) list[head] = temp;

        //Stream.of(list).forEach(x-> System.out.println(x+","));
        for (int i : list) {
            System.out.print(i);
            System.out.print(",");
        }
        System.out.println("");

        if (left > right) return;

        //递归 左块
        if (left < head) {
            quick(list, left, head);
        }
        //递归右块
        if (head + 1 < right) {
            quick(list, head + 1, right);
        }

    }

    /***
     * 交换排序
     */
    @Test
    public void sortNormal() {

        List<Integer> arrayList = Arrays.asList(25, 10, 22, 30, 45, 53, 12, 43);
        int[] list = arrayList.stream().mapToInt(x -> x).toArray();


        for (int i = 0; i < list.length; i++) {
            for (int j = 0; j < i; j++) {
                if (list[i] <= list[j]) {
                    int temp = list[i];
                    list[i] = list[j];
                    list[j] = temp;
                }
            }
        }

        for (int i : list) {
            System.out.print(i);
            System.out.print(",");
        }
        System.out.println("");
    }



}