Array_from_permutation.java

import java.util.Arrays;

public class Array_from_permutation {
    public static void main(String[] args) {
        int[] nums = {0,2,1,5,3,4};
        int[] arr = new int[nums.length];
        for (int i = 0; i < nums.length; i++) {
            arr[i] = nums[nums[i]];
        }
        System.out.println(Arrays.toString(arr));
    }
    //this solution is ok but there is a solution in O(1) space complexity -
//        int n = nums.length;
//        for(int i=0; i<n; i++){
//        // this is done to keep both old and new value together.
//        // going by the example of [5,0,1,2,3,4]
//        // after this nums[0] will be 5 + 6*(4%6) = 5 + 24 = 29;
//        // now for next index calulation we might need the original value of num[0] which can be obtain by num[0]%6 = 29%6 = 5;
//        // if we want to get just he new value of num[0], we can get it by num[0]/6 = 29/6 = 4
//        nums[i] = nums[i] + n*(nums[nums[i]] % n);
//    }
//
//        for(int i=0; i<n; i++){
//        nums[i] = nums[i]/n;
//    }
//
//        return nums;

}