算法导论第七章（快速排序）

package chapter6_sort;public class quickSort {public static void main(String[] args) {int[] arr = new int[5];for (int i = 0; i < 5; i++) {arr[i] = (int) (Math.random() * 100);}quickSortFunction(arr, 0, arr.length - 1);for (int i = 0; i < arr.length; i++) {System.out.println(arr[i]);}}private static void quickSortFunction(int[] arr, int p, int r) {if (p < r) {int q = partition(arr, p, r);quickSortFunction(arr, p, q - 1);quickSortFunction(arr, q + 1, r);}}private static int partition(int[] arr, int p, int r) {int x = arr[r];int i = p - 1;for (int j = p; j < r; j++) {if (arr[j] < x) {i += 1;int num = arr[i];arr[i] = arr[j];arr[j] = num;}}arr[r] = arr[i + 1];arr[i + 1] = x;return i + 1;}}