Java實現堆排序

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輸入一個數m表示要排序的數的多少，隨機產生m個0~10000之間的數進行堆排序。

import java.util.Random;import java.util.Scanner;import org.junit.Test;public class Heap_Sort {    public static void makeHeap(int A[], int n) {        A[n] = A[0];        for (int i = n / 2; i >= 1; i--) {            shift_down(A, n, i);        }    }    private static void shift_down(int A[], int n, int i) {        boolean done = true;        while (done && i * 2 <= n) {            i = i * 2;            if ((i + 1) <= n && A[i + 1] > A[i])                i++;            if (A[i / 2] < A[i])                swap(A, i / 2, i);        }    }    private static void swap(int a[], int x, int y) {        int t;        t = a[x];        a[x] = a[y];        a[y] = t;    }    public static void sortHeap(int A[], int n) {        makeHeap(A, n);        swap(A, n, 1);        for (int i = n - 1; i > 1; i--) {            shift_down(A, i, 1);            swap(A, i, 1);        }    }    public static void main(String[] args) {        Scanner sc = new Scanner(System.in);        int n = sc.nextInt();        int A[] = new int[n + 1];        Random r = new Random();        for (int i = 0; i < n; i++) {            A[i] = r.nextInt(10000);        }        sortHeap(A, n);        for (int i = 1; i <= n; i++) {            System.out.print(A[i] + "\t");        }    }}

 

Java實現堆排序