# Leetcode - Sort Colors Solution

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.

**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]
```

**Example 3:**

```
Input: nums = [0]
Output: [0]
```

**Example 4:**

```
Input: nums = [1]
Output: [1]
```

**Constraints:**

`n == nums.length`

`1 <= n <= 300`

`nums[i]`

is`0`

,`1`

, or`2`

.

**Follow up:**

- Could you solve this problem without using the library's sort function?
- Could you come up with a one-pass algorithm using only
`O(1)`

constant space?

## Solution in Python

```
from collections import Counter
class Solution:
def sortColors(self, nums: List[int]) -> None:
"""
Do not return anything, modify nums in-place instead.
"""
count = Counter(nums)
index = 0
for i in [0,1,2]:
while count[i]:
nums[index] = i
count[i] -= 1
index+=1
```