Sort an Array of 0s, 1s and 2s

Sir your mail id ..i have some doubts

sir How the complexity will ne O n
When we have 3for loops
I think it will greater than that

So good explanation ...thanks!

A simple approach I came up with. After the first pass, all the zeroes are sent to the left. After the second pass, all the ones are sent to the right of zeroes. Here is the code:
A = [0, 1, 2, 1, 1, 1, 0, 2, 2, 0, 1, 2]
left = 0; right = 0
while right < len(A):
if A[right] == 0:
A[left], A[right] = A[right], A[left]
left += 1
right += 1

left = 0; right = 0
while right < len(A):
if A[right] == 1:
A[left], A[right] = A[right], A[left]
left += 1
elif A[right] == 0:
left += 1
right += 1

print(A)

Edit: This approach is used in Quicksort for moving all the elements lesser than pivot to its left and greater than pivot to its right.

Space complexity?

Was a classic DNF problem, should have shown that. Binge watching your algos Playlist, good job.

Sir can we use bubble sort as well

In real scenarios you will most likely be sorting the items with three tags or 0,1,2 as objects that have real data in them. This approach wouldn't work on that.

Can we use Arrays.sort(a);

Thanks, now I got a clear picture.

How to get 0,2,1 from above array