递归实现二分查找

闲来无事，写了个递归实现二分查找的小程序，权当温故了

#include 

//递归实现二分法查找,返回值为所在数组中的下标 
int search(int *a,int head,int tail,int target)
{
	int middle = (head+tail)/2;
	
	printf("_________________\n");
	printf("head=%d,middle=%d,tail=%d\n",head,middle,tail);
	
	if(*(a+middle) == target)
	{
		return middle;
	}
	if(head>tail)
	{
		return -1;
	}
	if(*(a+middle)>target)
	{
		tail = middle-1;
	}
	if(*(a+middle)