Bubble, binary interpolation and fast sorting algorithm

1. Bubble Sort Algorithm

Process:

1. Iterate through the array, each 22 adjacent elements for comparison, such as $a[$i]> $a [$i +1] then swap position, each comparison to eliminate a reverse order.

2. After each cycle, the next time you need to cycle the number of times reduced by 1.

<?php  
//bubble sort  
$arr = Createarr;  
Printarr ($arr);  
Popsort ($arr);  
Printarr ($arr);  
      
function Createarr ($num =10) {  
    $arr = array ();  
    For ($i =0 $i < $num; $i + +) {  
        Array_push ($arr, Mt_rand (0,999));  
    }  
    return $arr;  
}  
      
function Printarr ($arr) {  
    echo ' arr: '. Implode (', ', $arr). ' <br> ';  
}  
      
Function Popsort (& $arr) {  
    for ($i =0, $length =count ($arr)-1; $i < $length; $i + +) {for  
        ($j =0; $j <$ length-$i; $j + +) {  
            if ($arr [$j]> $arr [$j +1]) {  
                $tmp = $arr [$j];  
                $arr [$j] = $arr [$j +1];  
                $arr [$j +1] = $tmp;  
            }}}  
? >

2. Two-point insertion sequencing

Process:

1. First, the original array is an ordered sequence, $low =0 $high =count ($arr)-1.

2. Compare the number to be inserted with the element in the middle of the array.

If it is larger than the middle element, then $low= $mid +1 as the beginning of the array of the next judgment.

If it is smaller than the middle element, then $high= $mid-1 as the end of the array for the next judgment.

3. Until the end of the $low> $high, $low is where the new element is inserted.

4. Move the element from $low in the array back one bit, and then insert the new element at the $low position.

<?php  
//Two-point insertion sequencing  
      
$arr = Createarr;  
$key = Mt_rand (0,99);  
Printarr ($arr);  
Echo ' key= '. $key. ' <br> ';  
Binsort ($arr, $key);  
Printarr ($arr);  
      
function Createarr ($num =10) {  
    $arr = array ();  
    For ($i =0 $i < $num; $i + +) {  
        Array_push ($arr, Mt_rand (0,99));  
    }  
    Sort ($arr); Ordered sequence return  
    $arr;  
}  
      
function Printarr ($arr) {  
    echo ' arr: '. Implode (', ', $arr). ' <br> ';  
}  
      
Function Binsort (& $arr, $key) {  
      
    $low = 0;  
    $high = count ($arr)-1;  
      
    while ($low <= $high) {  
        $m = $low + (int) (($high-$low)/2);  
        $mkey = $arr [$m];  
        if ($key >= $mkey) {  
            $low = $m + 1;  
        } else{  
            $high = $m-1;  
        }  
    }  
      
    Moves the element after the insertion position, inserting the new element for  
    ($i =count ($arr)-1; $i >= $low; $i-) {  
        $arr [$i +1] = $arr [$i];  
    }  
      
    $arr [$low] = $key;  
}  
? >