For an online game I create an initial PHP array with 36 values: A-Z 0-9. A random script remix the array, i.e

[0] R
[1] 4
[2] N
[3] d
...
[35] 8

Once done the script assigns 6 signs to each of the 6 players via a chunk($arr,6).

Player 1 [0] = [R,4,n,d,O,M]
Player 2 [1] = [p,2,s,Z,k,u]
...
Player 6 [5] = [J,r,V,5,z,8]

The question is: once the table of players has been reordered alphabetically, is there an algorithmic way to recreate the initial distribution?

To simplify the question:

Initial array

[0] = abc
[1] = def
[2] = ghi
[3] = jkl
[4] = mno
[5] = pqr

Random order permutation [0,1,2,3,4,5] -> [2,5,0,3,1,4]:

[2] = ghi
[5] = pqr
[0] = abc
[3] = jkl
[1] = def
[4] = mno

Result:

new order     [0]   [1]   [2]   [3]   [4]   [5] 
value         ghi   pqr   abc   jkl   def   mno
former order  [2]   [5]   [0]   [3]   [1]   [4] -> random permutation

To retrieve former order I must find the way to produce the array [2,4,0,3,5,1]:

 new order   [2]   [4]   [0]   [3]   [5]   [1]          
 value       abc   def   ghi   jkl   mno   pqr  -> initial array order

How to obtain this array [2,4,0,3,5,1] from random permutation [2,5,0,3,1,4] ?