C语言 函数实现有序数组的二分法查找

int binary_search(int arr[] ,int x,int sz)//本质上arr是一个指针，仅存储数组第一个元素地址 
{
	//int sz = sizeof(arr) / sizeof(arr[0]);
	int left = 0;
	int right = sz - 1;
	while (left<=right)
	{
		int mid = (left + right)/2;
		if (x < arr[mid])
		{
			right = mid - 1;
		}
		else if (x > arr[mid])
		{
			left = mid + 1;
		}
		else 
		{
			return mid;
		}
	}
	return -1;
}

main()
{
	int k = 7;
	int arr[] = {1,2,3,4,5,6,7,8,9,10};
	int sz = sizeof(arr) / sizeof(arr[0]);
	int ret = binary_search(arr,k,sz);//数组传到形参中仅传输数组第一个元素地址，避免空间浪费
	if (ret != -1)
	{
		printf("下标是：%d\n", ret);
	}
	else
	{
		printf("找不到");
	}
	return 0;
}//有序二分查找