[Solved] Given an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue. We will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively.

Question

Given an array `nums` with `n` objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue.

We will use the integers `0``1`, and `2` to represent the color red, white, and blue, respectively.

You must solve this problem without using the library’s sort function.

Example 1:

```Input: nums = [2,0,2,1,1,0]
Output: [0,0,1,1,2,2]
```

Example 2:

```Input: nums = [2,0,1]
Output: [0,1,2]
```

Constraints:

• `n == nums.length`
• `1 <= n <= 300`
• `nums[i]` is either `0``1`, or `2`.

Follow up: Could you come up with a one-pass algorithm using only constant extra space?

Python Solution

```class Solution:
def sortColors(self, A: List[int]) -> None:
"""
Do not return anything, modify nums in-place instead.
"""
l = 0
r = len(A)-1
scan = 0

while scan<=r:
if A[scan]==0:
A[scan],A[l] = A[l],A[scan]
l+=1
scan+=1
elif A[scan]==2:
A[scan],A[r] = A[r],A[scan]
r-=1
else:
scan+=1
return(A)```