Find Three Largest Numbers

threeLargestNumbers.py

#---------------------------------------------------------
#---------Three Largest Numbers----------
#----------------------------------------------------------

# this function returns three largest numbers
# complexity O(2n) = O(n) where n is length of array
def threeLargestNumbers(numbers):
	if len(numbers) < 4:
		return numbers
	largest = [float("-inf")]*3
	for i in numbers :
		small = 0
		for j in  range(1,3):
			if largest[j] < largest[small]:
				small = j
		if largest[small] < i:
			largest[small] = i
			
	return largest
	
print(threeLargestNumbers([9,2,3,4,5,6,7,8]))