def find_smallest(arr):
	"""
	查找数组中最小元素的索引
	:param arr: 未排序数组
	:return: 返回数组中最小元素的索引
	"""
	smallest = arr[0]
	smallest_index = 0
	for i in range(1, len(arr)):
		if arr[i] < smallest:
			smallest = arr[i]
			smallest_index = i
	return smallest_index