#include
#define?M?100
#define?N?5
/*..利用快速排序?qū)?shù)組按升序排序..*/
int?partition?（int?key[]int?lowint?high）
{?
	int?k;
	k?=?key[low];
	while（low?	{
		while（low=?k）?high--;
		key[low]?=?key[high];
		while（low		key[high]?=?key[low];
	}
	key[low]?=?k;
	return?low;
}
void?QSort（int?str[]int?lowint?high）
{
	int?k;
	if（low?	{
??????k?=?partition（strlowhigh）;
	??QSort（strlowk-1）;
	??QSort（strk+1high）;
	}
}
/*...求中項(xiàng)...*/
void?mid（int?s[]int?i?int?r[]）
{
	int?j=5*i;
	QSort（sjj+4）;
	r[i]=s[j+2];
}
/*...求數(shù)組的第K小元素...*/
int??select（int?A[]int?pint?k）
{
	int?qi=0jst;
	int?mc[M]small[M]mid1[M]big[M];
	if（p<44）?
	{
		/*...直接排序...*/
		QSort（A0p-1）;
		return?A[k-1];
	}
	/*...分成q組，每組5個(gè)元素...*/
	q=p/5;
	/*...求各組中項(xiàng)...*/
	for（j=0;j	{
		mid（Ajc）;
	}
	/*...遞歸調(diào)用求中項(xiàng)