Question

I’ve a strange question: Which is the smart/best way to order an array of number like this

[1,1,2,2,3,3,4,4] 

to this

[1,2,3,4,1,2,3,4]

The idea is to balance the list in order to give a sort of priority to each element of the list.
Language could be php, it does not matter that much

Answer 1

lets say we have [1,1,2,2,2,2,3,3]
Take first set of equal numbers and put it in seperate arrays ( vertically )

1 1 

similarly for second set of equal numbers and so on

1 1 
2 2 2 2
3 3 3

Concat the arrays to get the result

[1,2,3][1,2,3][2,3][2]