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 flag 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

The input is an array of $0's$, $1's$ and $2's$

Output

The output is a printed 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