A.内部排序(直接加载到内存进行排序):包括交换式排序(冒泡和快速法)、选择式排序、插入式排序
B.外部排序(因数据量大,需借助外部存储进行排序):包括合并排序、直接合并排序
【冒泡排序:从后向前,依次比较相邻元素的排序码,若发现逆序则交换,一轮结束后,再来一轮,直到所有相邻数无逆序,即按顺序排完】
复制代码 代码如下:
function maoPao($arr,$style)//【默认传递的是值,不是地址。如果在$arr前加个&,则和$arr1指向同一个地址,函数外的$arr1也被排好了】
{
$temp=0;
$flag=false;
for($i=0;$i
for($j=0;$j
if($style=='bts') $op=$arr[$j]else if($style=='stb') $op=$arr[$j]>$arr[$j+1];
if($op)
{
$temp=$arr[$j];
$arr[$j]=$arr[$j+1];
$arr[$j+1]=$temp;
$flag=true;
}
}
if($flag==false)
{
break;//当一次横向循环下来flag==false;说明纵向循环里每次相邻元素比较大小时if条件均不满足,即从小到大已排好,无需再横向循环
}
}
foreach ($arr as $key => $value)
{
echo $value.',';
}
}
$arr1=array(101,101,-9,-8,0,76,1,57,43,90,23,-56);
maoPao($arr1,'stb');//small to big
【选择排序:第二个数至第n个数分别与第一个数比较,进行交换,第三个数至第n个数分别与第二个数比较,进行交换,直到排完】
复制代码 代码如下:
function selectSort($arr,$style)
{
$temp=0;
$flag=false;
for($i=0;$i
for($j=$i+1;$j
if($style=='bts') $op=$arr[$i]else if($style=='stb') $op=$arr[$i]>$arr[$j];
if($op)
{
$temp=$arr[$i];
$arr[$i]=$arr[$j];
$arr[$j]=$temp;
$flag=true;
}
}
if($flag==false)
{
break;
}
}
foreach ($arr as $key => $value)
{
echo $value.',';
}
}
$arr1=array(21.5,33,90,7,-4,5,55,11);
selectSort($arr1,'stb');
复制代码 代码如下:
function selectSort($arr,$style)
{
$temp=0;
$flag=false;
for($i=0;$i
for($j=$i+1;$j
if($style=='bts') $op=$arr[$i]else if($style=='stb') $op=$arr[$i]>$arr[$j];
if($op)
{
$temp=$arr[$i];
$arr[$i]=$arr[$j];
$arr[$j]=$temp;
$flag=true;
}
}
if($flag==false)
{
break;
}
}
foreach ($arr as $key => $value)
{
echo $value.',';
}
}
$arr1=array(21.5,33,90,7,-4,5,55,11);
selectSort($arr1,'stb');
echo "
";

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