From 3f4af66f2b19db6b73d52f31ef594e0a3c837e6d Mon Sep 17 00:00:00 2001
From: Alexchent <1023615292@qq.com>
Date: Sun, 4 Jul 2021 23:03:57 +0800
Subject: [PATCH] =?UTF-8?q?=E5=86=92=E6=B3=A1=E6=8E=92=E5=BA=8F?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 codehero/perg_match.php     | 1 +
 suanfa/Base/bubble_sort.php | 1 +
 suanfa/Base/quick_sort.php  | 1 +
 3 files changed, 3 insertions(+)
 create mode 100644 codehero/perg_match.php
 create mode 100644 suanfa/Base/bubble_sort.php
 create mode 100644 suanfa/Base/quick_sort.php

diff --git a/codehero/perg_match.php b/codehero/perg_match.php
new file mode 100644
index 0000000..99086df
--- /dev/null
+++ b/codehero/perg_match.php
@@ -0,0 +1 @@
+<?php
/**
 * Created by PhpStorm.
 * User: chentao
 * Date: 2021/7/4
 * Time: 9:18 PM
 */

$str = 'src="http:www.youzu.com/1.png" width="100" width="100"';

//echo preg_match("/src=*(.*)*/", $str);


\ No newline at end of file
diff --git a/suanfa/Base/bubble_sort.php b/suanfa/Base/bubble_sort.php
new file mode 100644
index 0000000..0a163d2
--- /dev/null
+++ b/suanfa/Base/bubble_sort.php
@@ -0,0 +1 @@
+<?php
/**
 * Created by PhpStorm.
 * User: chentao
 * Date: 2021/7/4
 * Time: 10:55 PM
 */

//冒泡排序的思想是：从第一个数开始，跟后面的数比较，如果比后面的数大则交换位置，那么更最后一个数比完，最大的数就排到了最后面
//接着再从头开始，比较剩下的n-1个数
//如此往复，直到最后一个数

//时间复杂度 O(n^2)
function bubble_sort($arr)
{
    $len = count($arr);
    if ($len < 2) return $arr;

    for($i=1; $i<$len; $i++) {
        for ($j=0; $j<$len-1;$j++) {
            if ($arr[$j] > $arr[$j+1]) {
                $tmp = $arr[$j];
                $arr[$j] = $arr[$j+1];
                $arr[$j+1] = $tmp;
            }
        }
    }
    return $arr;
}

$sort = bubble_sort([2,6,19,4,5,8,3]);

var_dump($sort);
\ No newline at end of file
diff --git a/suanfa/Base/quick_sort.php b/suanfa/Base/quick_sort.php
new file mode 100644
index 0000000..2128d1e
--- /dev/null
+++ b/suanfa/Base/quick_sort.php
@@ -0,0 +1 @@
+<?php
/**
 * Created by PhpStorm.
 * User: chentao
 * Date: 2021/7/4
 * Time: 10:42 PM
 */

//快速排序的思路，就是选中一个基准数，比基准数大的放在右区间，否则放在左区间，这样基准数的位置就确定了，
//之后就是对区间重复上诉操作，当所有的区间只有一个数的时候就排好序了

//快速排序的时间平均时间复杂度是 O(nlog2n) 最坏时间复杂度是O(n^2)
function quick_sort($arr) {
    if (count($arr) < 2) return $arr;

    $base = $arr[0];
    $right = [];
    $left = [];
    unset($arr[0]);

    foreach ($arr as $value) {
        if ($value >= $base) {
            $right[] = $value;
        } else {
            $left[] = $value;
        }
    }

    if (count($left)) $left = quick_sort($left);
    if (count($right)) $right = quick_sort($right);
    return array_merge($left, [$base], $right);
}

$sort = quick_sort([2,6,19,4,5,8,3]);

var_dump($sort);
\ No newline at end of file