JAVA语言之归并排序

package com.paixu;


public class guibing {

public static void main(String[] args) {
   int[] A=new int[]{5,3,4,2,1};
   A=guibing.mergeSort(A, 5);
  for(int i=0;i<5;i++){
  System.out.print(A[i]+" ");
  }
}


public static int[] mergeSort(int[] A, int n) {
        sort(A,0,n-1);
        return A;
    }

public static void sort(int[] A,int low,int high){
if(low<high){
int middle=(low+high)/2;
   //分左
sort(A,low,middle);
//分右
sort(A,middle+1,high);
//合并
merge(A,low,middle,high);
}
}
    
public static void merge(int[] A,int low,int middle,int high){
       int left=low;
       int right=middle+1;
       int aa=0;
       int[] ss=new int[high-low+1];
  //先将左右子数组其中一个数组排好序
       while(left<=middle && right<=high){
 if(A[left]<=A[right]){
 ss[aa++]=A[left++];
 }else{
 ss[aa++]=A[right++];
 }
    
  }
       //左子数组还有则自动排后面
  while(left<=middle){
  ss[aa]=A[left];
  left++;
  aa++;
  }
  //右子数组还有则自动排后面
  while(right<=high){
  ss[aa]=A[right];
  right++;
  aa++;
  }
       int temp=0;
       while((temp+low)<=high){
      A[temp+low]=ss[temp];
      temp++;
       }

    }
}