Suppose you are given an array

```
    $input = array(1,1,1,2,2,3,3,4,5,5);

```

Where you want to split the array so that you have all the 1's in one array, all the 2's in one array, etc.

However, you don't know if the $input array will only contain only 1's, or only 1's and 2's, or how many ever numbers there are.

The numbers are numerically ordered.