// 冒泡法
function bubbleSort($array)
{
!is_array($array) ? '非数组' : '';
$len = count($array);
for ($i = 0; $i < $len; $i++) {
for ($j = $len -1 ; $j > $i; $j--) {
if ($array[$j] > $array[$j-1]) {
$temp = $array[$j-1];
$array[$j-1] = $array[$j];
$array[$j] = $temp;
}
}
}
return $array;
}
$a = array(1, 5, 2, 7, 15, 12, 70, 100, 60);
print_r(bubbleSort($a));
echo '<br />';
// 二分查找法 假设$array 是从小到大的线性数组
function binSearch($array, $findvalue)
{
$low = 0;
$high = count($array) - 1;
while ($low <= $high) {
$mid = intval(($low + $high) / 2);
if ($array[$mid] == $findvalue) {
return $mid;
} elseif ($array[$mid] > $findvalue) {
$high = $mid - 1;
} else {
$low = $mid + 1;
}
}
return false;
}
$b = array(1, 2, 3, 4, 56, 70, 121, 300, 500);
echo binSearch($b, 121);
echo '<br />';
// 16进制转10进制 内置函数 hexdec
function hexToDec($H)
{
$array = array('F' => 15, 'E' => 14, 'D' => 13, 'C' => 12, 'B' => 11, 'A' => 10);
$len = strlen($H);
$sum = 0;
for ($i = 0; $i < $len; $i++) {
$bit = substr($H, $i, 1);
if (!is_numeric($bit)) {
$bit = $array[strtoupper($bit)];
}
$e = $len - $i - 1;
$sum += pow(16, $e) * $bit;
}
return $sum;
}
echo hexToDec('ff1');
echo '<br />';
// 选择排序法
function selectSort($array)
{
!is_array($array) ? '非数组' : '';
$len = count($array);
for ($i = 0; $i < $len; $i++) {
for ($j = $i + 1; $j < $len; $j++) {
if ($array[$j] > $array[$i]) {
$temp = $array[$i];
$array[$i] = $array[$j];
$array[$j] = $temp;
}
}
}
return $array;
}
$a = array(2,5,1,6,11,8,15,9);
print_r(selectSort($a));
//快速排序（数组排序）
function quicksort($array)
{
if (count($array) <= 1)
return $array;
$key = $array[0];
$left_arr = array();
$right_arr = array();
for ($i = 1; $i < count($array); $i++) {
if ($array[$i] <= $key) {
$left_arr[] = $array[$i];
} else {
$right_arr[] = $array[$i];
}
}
//运用递归
$left_arr = quicksort($left_arr);
$right_arr = quicksort($right_arr);
return array_merge($left_arr, array($key), $right_arr);
}
$a = array(1,3,7,2,5,10,9,21);
print_r(quicksort($a));
// 求素数
// 方法一：直接法
$a = 100000;
$array = array();
$array[] = 1;
$array[] = 2;
for ($i = 3; $i <= $a; $i++) {
$flags = true;
if($i % 2 == 0 || $i % 3 == 0 || $i % 5 == 0){
continue;
}
for ($j = 2; $j < $i; $j++) {
if ($i % $j == 0) {
$flags = false;
break;
}
}
if(!$flags){
continue;
}
$array[] = $i;
}
//print_r($array);
// 方法二：优化法
function prime5($MAX)
{
$data[0] = 2;
$total = 1;
for ($i = 3; $i <= $MAX; $i += 2) {
$sqrt = ceil(sqrt($i));
$isp = true;
for ($j = 0; $j < $total && $data[$j] <= $sqrt; $j++) {
if ($i % $data[$j] === 0) {
$isp = false;
break;
}
}
if ($isp) {
//$total = $total + 1;
$data[$total] = $i;
$total = $total + 1;
}
}
return $data;
}
$a = prime5(20000);
print_r($a);
<?php//冒泡排序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 $demo;}//插入排序function charu_sort($demo){
$num = count($demo); for($i=1;$i<$num;$i++){ $temp=$demo[$i]; $dqweizhi = $i-1;//记录当前位置 while(($dqweizhi>=0)&&($temp<$demo[$dqweizhi])){ $demo[$dqweizhi+1] = $demo[$dqweizhi]; $dqweizhi--; } $demo[$dqweizhi+1]
= $temp; } return $demo;}//选择法排序function select_sort($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 $demo;}//快速排序function quick_sort($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);?>
