递归折半查找，C语言

#include <stdio.h>

/*折半查找*/
int binary_Search(int* arry, int key, int left, int right)  //返回key所在的数组下标
{
	int mid = (left + right) / 2;
	if (arry[mid] == key)
		return mid;
	else if (arry[mid] > key)
		right = mid - 1;
	else left = mid + 1;
	if (left > right)            //没有找到
		return -1;
	else return binary_Search(arry, key, left, right);
}

int main()
{
	int arry[15] = { 1,3,5,7,8,9,10,12,15,19,78,20,22,28,29 };
	int key;         //需查找的数
	printf("请输入你需要查找的数：\n");
	scanf("%d", &key);
	printf("%d\n",binary_Search(arry, key, 0, 15));
	return 0;
}