java归并排序

/**
 * Copyright (C), 2018-2019, LMaWC
 * FileName: Application
 * Author:   neo
 * Date:     2019/3/20 19:35
 * Description:
 * History:
 * <author>          <time>          <version>          <desc>
 * 作者姓名           修改时间           版本号              描述
 */
package com.test;

import com.sun.jndi.cosnaming.CNCtx;
import org.omg.CORBA.ARG_IN;
import sun.security.util.Length;

import javax.swing.text.Highlighter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

/**
 * 〈一句话功能简述〉<br> 
 * 〈〉
 *
 * @author neo
 * @create 2019/3/20
 * @since 1.0.0
 */
public class Application {
    private static  void mergeSort(int[] a,int[] tmpArray,int left,int right){
        if(left<right){
            // 分成两个数组进行排序
            int center = (left+right)/2;
            mergeSort(a,tmpArray,left,center);
            mergeSort(a,tmpArray,center+1,right);

            // 将两个数组进行合并
            merge(a,tmpArray,left,center+1,right);
        }
    }

    public static void mergeSort(int[] a){
        int[] tmpArray = new int[a.length];
        mergeSort(a,tmpArray,0,a.length-1);
    }

    private static void merge(int[] a,int[] tmpArray,int lefPos,int rightPos,int rightEnd){
        int leftEnd = rightPos-1;
        int tmpPos = lefPos;
        int numElements = rightEnd-lefPos+1;

        // Main loop
        while (lefPos<=leftEnd&&rightPos<=rightEnd){
            // 把比较的数据全都放到tmp数组里
            if(a[lefPos]<=a[rightPos]){
                tmpArray[tmpPos++] = a[lefPos++];
            }else {
                tmpArray[tmpPos++] = a[rightPos++];
            }
        }
        while (lefPos<=leftEnd){
            tmpArray[tmpPos++] = a[lefPos++];
        }
        while (rightPos<=rightEnd){
            tmpArray[tmpPos++] = a[rightPos++];
        }

        // copy tmpArray back
        for(int i = 0;i< numElements;i++,rightEnd--){
            a[rightEnd] = tmpArray[rightEnd];
        }
    }

    public static void main(String[] args) {
        int[] nums={11,1,6,1,6,7,1,7,12};
        mergeSort(nums);
        for(int  i = 0;i<nums.length;i++){
            System.out.println(nums[i]);
        }
    }




}