Java: Sort Elements by Frequency

Difficulty Level: EASY

Problem Statement:

Print the elements of an array in the decreasing frequency if 2 numbers have the same frequency then print the one which came first.

Input:

arr[] = {4, 6, 4, 8, 6, 7, 8, 8}

Output:

arr[] = {8, 8, 8, 4, 4, 6, 6, 7}