Java 代码

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class Main {
    public static void main(String[] args) throws IOException {
        InputStreamReader inputStreamReader = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        int num = Integer.parseInt(bufferedReader.readLine());
        int [] array = new int [num];
        String [] result = bufferedReader.readLine().split(" ");
        for (int i = 0;i<num;i++){
            array[i] = Integer.parseInt(result[i]);
        }
        merge_sort(array,0,array.length-1);
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i]+" ");
        }
        bufferedReader.close();
    }
    public static void merge_sort(int [] array , int left ,int right){
        if (left>=right) return;
        int middle = (left+right)/2;
        merge_sort(array,left,middle);
        merge_sort(array,middle+1,right);
        merge(array,left,middle,middle+1,right);
    }
    public static void merge(int [] array ,int leftStart ,int leftEnd , int rightStart , int rightEnd) {
        int i = leftStart;
        int j = rightStart;
        int k = 0;
        int[] tmp = new int[rightEnd - leftStart + 1];
        while (i <= leftEnd && j <= rightEnd) {
            if (array[i] > array[j]) {
                tmp[k++] = array[j++];
            } else {
                tmp[k++] = array[i++];
            }
        }
        while (i <= leftEnd) {
            tmp[k++] = array[i++];
        }
        while (j <= rightEnd) {
            tmp[k++] = array[j++];
        }
        k = leftStart;
        for(int element : tmp){
            array[k++] = element;
        }
    }
}