From 83d334356b50c6ad082034356e3dcc1c97aeef64 Mon Sep 17 00:00:00 2001 From: ehlxr Date: Tue, 28 Dec 2021 20:33:27 +0800 Subject: [PATCH] update at 2021-12-28 20:33:27 by ehlxr --- .../ehlxr/algorithm/sort/QuickSort.java | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 budd-common/src/main/java/io/github/ehlxr/algorithm/sort/QuickSort.java diff --git a/budd-common/src/main/java/io/github/ehlxr/algorithm/sort/QuickSort.java b/budd-common/src/main/java/io/github/ehlxr/algorithm/sort/QuickSort.java new file mode 100644 index 0000000..cf885c2 --- /dev/null +++ b/budd-common/src/main/java/io/github/ehlxr/algorithm/sort/QuickSort.java @@ -0,0 +1,77 @@ +/* + * The MIT License (MIT) + * + * Copyright © 2021 xrv + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package io.github.ehlxr.algorithm.sort; + +import java.util.Arrays; + +/** + * @author ehlxr + * @since 2021-12-28 19:57. + */ +public class QuickSort { + public static void main(String[] args) { + int[] arrs = new int[]{3, 2, 5, 7, 1, 9}; + sort(arrs, 0, arrs.length - 1); + + System.out.println(Arrays.toString(args)); + } + + public static void sort(int[] arrs, int p, int r) { + if (p >= r) { + return; + } + + int k = partition(arrs, p, r); + + sort(arrs, p, k - 1); + sort(arrs, k + 1, r); + } + + public static int partition(int[] arrs, int p, int r) { + int i = p; + int pivot = arrs[r]; + for (int j = p; j < r; j++) { + if (arrs[j] < pivot) { + if (j != i) { + swap(arrs, i, j); + } + i++; + } + } + + swap(arrs, i, r); + System.out.println("i=" + i); + + return i; + } + + public static void swap(int[] arrs, int i, int j) { + int temp = arrs[i]; + arrs[i] = arrs[j]; + arrs[j] = temp; + } + + +}