Challenge: Dutch National Flag Problem

Problem Statement

Implement a function that sorts an array of $0's$, $1's$ and $2's$. This is called the Dutch National Problem. Since the number $O$ can be represented as the blue color, $1$ as the white color, and $2$ as the red color, we want the array to form the Dutch flag.

Try solving this problem inplace and in linear time without using any extra space!

Input

An array of $0's$, $1's$ and $2's$

Output

An array where the numbers $0$, $1$, and $2$ are sorted.

Sample Input

arr = {2, 0, 0, 1, 2, 1, 0}

Sample Output

0 0 0 1 1 2 2