c语言二分法查找数组中一个数字的下标位置

int binary_search(int arr[], int k, int left, int right)
{
	//int right = sizeof(arr) / sizeof(arr[0]) - 1;放在这里错误，arr是指针，长度为4个字节，right=0
	while (left <= right)
	{
		int mid = left + (right - left) / 2;//每次都要改变，所以要循环
		if (arr[mid] > k)
		{
			right = mid - 1;
		}
		else if (arr[mid] < k)
		{
			left = mid + 1;
		}
		else
		{
			return mid;
		}
	}
	return -1;
}

int main()
{
	int arr[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };//初始化数组可以替换
	int k = 0;
	int left = 0;
	int right = sizeof(arr) / sizeof(arr[0]) - 1;//在哪定义在哪使用
	printf("输入需要找到数字\n");
	scanf("%d",&k);
	int ret = binary_search(arr, k, left, right);
	if (ret == -1)
	{
		printf("找不到\n");
	}
	else
	{
		printf("找到了,下标是:%d\n", ret);
	}
	//int mid = (left+right)/2;
	return 0;
}