PHP写的几个常用算法

class CArithmetic

{

/**

* 二分算法

*

* @param object $pParam

* $aData = $pParam->aData; //数组数据

$iLow = $pParam->iLow; //开始位置

$iHigh = $pParam->iHigh; //结束位置

$iFind = $pParam->iFind; //查找的值

* @return int 需要查找的值

*/

public function Dichotomy($pParam)

{

$aData = $pParam->aData;

$pParam->iSort = 1;

$aData = $this->QuickSort($pParam);

$iLow = $pParam->iLow;

$iHigh = $pParam->iHigh;

$iFind = $pParam->iFind;

if ($iLow > $iHigh)

return false;

$iMid = intval(($iLow+$iHigh)/2);

if ($iFind == $aData[$iMid])//刚好在中间

{

return $iFind;

}

elseif ($iFind < $aData[$iMid])//要查找的数据比数据中间的数据小

{

$pData =

(object)array('aData'=>$aData,'iLow'=>$iLow,'iHigh'=>$iMid-1,'iFind'= >$iFind);

return $this->Dichotomy($pData);

}

else

{

$pData =

(object)array('aData'=>$aData,'iLow'=>$iMid+1,'iHigh'=>$iHigh,'iFind' =>$iFind);

return $this->Dichotomy($pData);

}

return false;

}

/**

* 快速排序法

*

* @param object $pParam

* $aData 需要排序的数组

* $iSort 排序类型 1-升序 2-降序

* @return array

*/

public function QuickSort($pParam)

{

$aData = $pParam->aData; //需要排序的数组

$iSort = property_exists($pParam,'iSort') ? $pParam->iSort : 0; //排序类型 1-ASC 2-DESC

$iCount = count($aData);

if ($iCount <= 1)

return $aData;

$iKey = $aData[0];//随机取一个中间值作为比较

$aDataLow = $aDataHigh = array();

if ($iSort == 1)//升序

{

for ($i=1;$i<$iCount;$i++)

{

if ($aData[$i] <= $iKey)

$aDataLow[] = $aData[$i];

else

$aDataHigh[] = $aData[$i];

}

$pDataLow = (object)array('aData'=>$aDataLow,'iSort'=>1);

$aDataLow = $this->QuickSort($pDataLow);

$pDataHigh = (object)array('aData'=>$aDataHigh,'iSort'=>1);

$aDataHigh = $this->QuickSort($pDataHigh);

return array_merge($aDataLow,array($iKey),$aDataHigh);

}

else

{

for ($i=$iCount-1;$i>0;$i--)

{

if ($aData[$i] <= $iKey)

$aDataLow[] = $aData[$i];

else

$aDataHigh[] = $aData[$i];

}

$pDataLow = (object)array('aData'=>$aDataLow,'iSort'=>2);

$aDataLow = $this->QuickSort($pDataLow);

$pDataHigh = (object)array('aData'=>$aDataHigh,'iSort'=>2);

$aDataHigh = $this->QuickSort($pDataHigh);

return array_merge($aDataHigh,array($iKey),$aDataLow);

}

}

/**

* 冒泡算法

*

* @param object $pParam

* $aData 需要排序的数组

* $iSort 排序类型 1-升序 2-降序

* @return array

*/

public function BubbleSort($pParam)

{

$aData = $pParam->aData; //需要排序的数组

$iSort = property_exists($pParam,'iSort') ? $pParam->iSort : 0; //排序类型 1-ASC 2-DESC

$iCount = count($aData);

if ($iCount <= 1)

return $aData;

if ($iSort == 1) //ASC

{

for ($i=0;$i<=$iCount-1;$i++)

{

for ($j=$i;$j<$iCount-1;$j++)

{

if($aData[$i] >= $aData[$j+1])

{

$temp = $aData[$i];

$aData[$i] = $aData[$j+1];

$aData[$j+1] = $temp;

}

}

}

}

else

{

for ($i=0;$i<=$iCount-1;$i++)

{

for ($j=$i;$j<$iCount-1;$j++)

{

if($aData[$i] <= $aData[$j+1])

{

$temp = $aData[$i];

$aData[$i] = $aData[$j+1];

$aData[$j+1] = $temp;

}

}

}

}

return $aData;

}

/**

* 获取时间

*

* @return int

*/

public function GetMicroTime()

{

list($usec, $sec) = explode(" ", microtime());

return ((float)$usec + (float)$sec);

}

}

$db = new CArithmetic();

//这个数组得先排序，按照由小到大排序

$aData = array(100,155,4,3,6,7,9,15,24);//

$iLow = 0;

$iHigh = count($aData);

$iFind = 6;

//$pData =

(object)array('aData'=>$aData,'iLow'=>$iLow,'iHigh'=>$iHigh,'iFind'=> $iFind);

$pData = (object)array('aData'=>$aData,'iSort'=>2);

$dStartTime = $db->GetMicroTime();

//$i = $db->Dichotomy($pData);

$aDataSort = $db->BubbleSort($pData);

$dEndTime = $db->GetMicroTime();

$iTime = $dEndTime - $dStartTime;

$iTime = number_format($iTime,6);

echo "Get result in $iTime seconds\n";

print_r($aDataSort); ?>