Php insert sorting method to implement array sorting _ PHP Tutorial

Php inserts a sorting method to implement array sorting instances. This article mainly introduces the php insert sort method to sort arrays. The example analyzes the principle and specific implementation skills of the insert sort method, some php Insertion sorting methods are available for array sorting instances.

This article mainly introduces the php insert sorting method to achieve array sorting. The example analyzes the principle and specific implementation skills of the insert sorting method, which has some reference value. For more information, see

This example describes how to sort arrays by using the php insert sorting method. Share it with you for your reference. The specific analysis is as follows:

The basic idea of insert sorting method is as follows: we also use cases to explain whether to sort data in ascending order by $ arr = array.

Implementation principle: assume (not actually created) that there is an ordered array $ arr = array (2) and compare it with $ arr [1] = 6. if 6> 2, move $ arr [0] to $ arr [1], and insert 6 to $ arr [0. Next, compare $ arr [2] = 3 with $ arr [1] = 2, 3> 2, then $ arr [1] = 2 continues and moves to the $ arr [2] position. the original $ arr [3] = 3 is inserted to the $ arr [1] position, insert 9 to the combined position. The final result is (9, 6, 3, 2 ). It can also be sorted through the count ($ arr)-1 large loop.

Code rule analysis:

First large loop: $ [1] to $ [0;
The second big cycle: $ [2] to $ [1], $ [1] to $ [0;
The third cycle: $ [3] to $ [2], $ [2] to $ [1], $ [1] to $ [0;

PHP code, using function encapsulation for ease of use

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Function insertSort (& $ arr ){ For ($ I = 1; $ I < p> <> // $ InsertVal indicates the number of inserts to be prepared. For ($ j = $ I; $ j> 0; $ j --){ If ($ arr [$ j]> $ arr [$ j-1]) { $ InsertVal = $ arr [$ j]; $ Arr [$ j] = $ arr [$ j-1]; $ Arr [$ j-1] = $ insertVal; } } } } $ Myarr = array (2, 6, 3, 9 ); InsertSort ($ myarr ); Echo" "; print_r($myarr); ?>

Code implementation analysis:

The first big cycle:

$ I = 1 array (2, 6, 3, 9)
$ J = 1 run 6 and 2 ratio: $ arr [1] = 2; $ arr [0] = 6, get (6, 2, 3, 9)

The second cycle:

$ I = 2 array (6, 2, 3, 9)
$ J = 2: execute 3 and 2: convert to $ arr [2] = 2, $ arr [1] = 3, get (6, 3, 2, 9)
$ J --, $ j = 1 execution $ arr [1] and $ arr [0] ratio: condition not true

The third cycle:

$ I = 3 array (6, 3, 2, 9)
$ J = 3 run 9 and 2 ratio: convert to $ arr [3] = 2, $ arr [2] = 9, get (6, 3, 9, 2)
$ J --, $ j = 2 run 9 and 3 ratio: change to $ arr [2] = 3, $ arr [1] = 9, get (6, 9, 3, 2)
$ J --, $ j = 1. execute 9 and 6: convert to $ arr [1] = 5, $ arr [0] = 9, and get (9, 6, 3, 2)

I hope this article will help you with php programming.

This article describes how to sort arrays by insert sorting in php. The example analyzes the principle and specific implementation skills of insert sorting...