Challenge 1: Gathering Zeros to the Start

Problem statement

In this problem, you have to implement the zerosToStart() function which will sort the elements of an Integer ArrayList such that all the zeros appear at left and other elements appear at the right.

Function prototype

void zerosToStart(ArrayList<Integer> arrList)

Output

A sorted ArrayList with zeros at the left i.e. starting indices and positive elements at the right.

Sample input

arrList = [5,0,20,4,0,0,9]

Sample output

arrList = [0,0,0,5,20,4,9]

Note: All non zero elements must appear in the original order.