PHP implements multiple solutions for bubble sorting

In actual PHP development, we will encounter a lot of sorting, and bubble sorting is also one of the common ones. If we want to do a good job in PHP development, then we must easily use PHP to implement bubbling. Sorting, this article will tell you about PHP bubble sorting! Let’s take a look at the various ways to implement bubble sorting in PHP!

Bubble sorting is very easy to understand and implement. Take sorting from small to large as an example:
Suppose The length of the array is N.
1. Compare the two adjacent data before and after. If the former data is greater than the latter data, the two data will be exchanged.
2. In this way, after traversing the 0th data to the N-1th data of the array, the largest data will "sink" to the N-1th position of the array.
3. N=N-1, if N is not 0, repeat the previous two steps, otherwise the sorting is completed.

Plan one:

<?php
function bubble1_sort($array)
{
    $count = count($array);
    if ($count <= 1) {
        return $array;
    }
    for ($i = 0; $i < $count; $i++) {
        for ($j = 0; $j < $count; $j++) {
            if ($array[$i] < $array[$j]) {
                $temp = $array[$i];
                $array[$i] = $array[$j];
                $array[$j] = $temp;
            }
        }
    }
    return $array;
}

Plan two:

<?php
function bubble2_sort($array)
{
    $count = count($array);
    if ($count <= 1) {
        return $array;
    }
    for ($i = 0; $i < $count; $i++) {
        for ($j = 1; $j < $count - $i; $j++) {
            if ($array[$j - 1] > $array[$j]) {
                $temp = $array[$j - 1];
                $array[$j - 1] = $array[$j];
                $array[$j] = $temp;
            }
        }
    }
    return $array;
}

Plan three:

Set a flag that is true if an exchange occurs on this trip, otherwise false. Obviously, if there is no exchange in one trip, it means that the sorting has been completed.

<?php
function bubble3_sort($array)
{
    $count = count($array);
    if ($count <= 1) {
        return $array;
    }
    $flag = true;
    $j = $count;
    while ($flag) {
        $flag = false;
        for ($i = 1; $i < $j; $i++) {
            if ($array[$i - 1] > $array[$i]) {
                $temp = $array[$i - 1];
                $array[$i - 1] = $array[$i];
                $array[$i] = $temp;
                $flag = true;
            }
        }
        $j--;
    }
    return $array;
}

Option 4:

If there is an array of 100 numbers, only the first 10 are unordered, and the next 90 are sorted and all are greater than the first 10 number, then after the first traversal, the last exchange position must be less than 10, and the data after this position must be in order. Record this position. The second time you just traverse from the head of the array to this position, That's it.

<?php

function bubble4_sort($array)
{
    $count = count($array);
    if ($count <= 1) {
        return $array;
    }
    $flag = $count;
    while ($flag > 0) {
        $k = $flag;
        $flag = 0;
        for ($j = 1; $j < $k; $j++) {
            if ($array[$j - 1] > $array[$j]) {
                $temp = $array[$j - 1];
                $array[$j - 1] = $array[$j];
                $array[$j] = $temp;
                $flag = $j;
            }
        }
    }
    return $array;
}

Option 5:

<?php

function bubble_sort($array)
{
    $count = count($array);
    if ($count <= 1) {
        return $array;
    }
    for ($i = $count - 1; $i > 0; $i--) {
        $flag = false;
        for ($j = 0; $j < $count; $j++) {
            if ($array[$j] > $array[$j + 1]) {
                $temp = $array[$j];
                $array[$j] = $array[$j + 1];
                $array[$j + 1] = $temp;
                $flag = true;
            }
        }
        if (!$flag)
            break;
    }
    return $array;
}

The above are the various methods of implementing bubble sorting in PHP. There are five in total. In fact, we understand the principle of one and the other four are natural. That’s it! I need help for everyone learning PHP!

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