Processing Java mode return Index of sorted array


This is my first post. I am using: Processing 4 1293 for Linux

In Java mode, I want to sort an array, but want to get the index of the sorted array. Example:

array = {1,4,2,4,1,4,3,4,5};   // this is my input}
sortedArrayIndex = {0,4,2,6,1,3,5,7,8} ; // this is what i want

If I use the built in sort function, it will return me the array {1,1,2,3,4,4,4,4,5} - but what I want is an array of indices of elements in the original array, as they’d appear if they were sorted.

In the input array, same elements cna appear multiple times. In our example - 1 is smallest but appears in indices 0 and 4 - hence the first two items in output array is 0 and 4.

I would like these indices of similar elements to be sorted as well - that is, 0 comes before 4, even tho elements 4 and 0 are the same, and 4 coming before 0 would also have represented a sorted array.

I would like some help on this. Thank you.

I found a solution here

in processing it would be

import java.util.Arrays;
import java.util.Comparator;
void setup() {
  final Integer[] idx = {0,1,2,3,4,5,6,7,8};
  Integer[] array = {1,4,2,4,1,4,3,4,5};   // this is my input
  // sortedArrayIndex = {0,4,2,6,1,3,5,7,8} ; // this is what i want

  Arrays.sort(idx, new Comparator<Integer>() {
      @Override public int compare(final Integer o1, final Integer o2) {
          return[o1], array[o2]);