PHP Instance code: All sorts of algorithms

　　

Bubble sort

function Maopao_sort ($demo) {

$num = count ($demo);

for ($i =0; $i < $num; $i + +) {

for ($j = $num-1; $j > $i; $j-) {

if ($demo [$j]< $demo [$j-1]) {

$temp = $demo [$j];

$demo [$j]= $demo [$j-1];

$demo [$j -1]= $temp;

}

}

}

return $demo;

}

Insert Sort

function Charu_sort ($demo) {

$num = count ($demo);

for ($i =1; $i < $num; $i + +) {

$temp = $demo [$i];

$dqweizhi = $i -1;//record current position

while ($dqweizhi >=0) && ($temp < $demo [$dqweizhi])) {

$demo [$dqweizhi +1] = $demo [$dqweizhi];

$dqweizhi--;

}

$demo [$dqweizhi +1] = $temp;

}

return $demo;

}

Sorting by Selection method

function Select_sort ($demo) {

$num = count ($demo);

For ($i =0 $i < $num-1; $i + +) {

$temp = $demo [$i];

$dqweizhi = $i;

for ($j = $i +1; $j < $num; $j + +) {

if ($demo [$j]< $temp) {

$temp = $demo [$j];

$dqweizhi = $j;

}

}

$demo [$dqweizhi]= $demo [$i];

$demo [$i]= $temp;

}

return $demo;

}

Quick Sort

function Quick_sort ($demo)

{

$num = count ($demo);

if ($num <=1) {

return $demo;

}

$key = $demo [0];

$left _array=array ();

$right _array=array ();

for ($i =1; $i < $num; $i + +) {

if ($demo [$i]<= $key) {

$left _array[]= $demo [$i];

}else{

$right _array[]= $demo [$i];

}

}

$left _array =quick_sort ($left _array);

$right _array=quick_sort ($right _array);

Return Array_merge ($left _array,array ($key), $right _array);

}

$test = Array (' 43 ', ' 154 ', ' 3 ', ' 78 ', ' 13 ', ' 284 ', ' 167 ', ' 2 ', ' 56 ', ' 2234 ', ' 121 ', ' 57 ', ' 345 ');

$sss = Quick_sort ($test);

Var_dump ($SSS);

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