CareerCup

Load into a simple array.
Use a shuffle like, Fisher-Yates shuffle. Every time you swap an element, print/return it. Keep track of last shuffled index.
While dumping the data, save the last shuffled index along the array.

This is just "merge k sorted arrays". Use merge sort.

@ChrisK

Your solution doesn't work for 132241043


Total combinations:
132241043
(13)22241043
13(22)241043
132(22)41043
1322(24)1043
(13)(22)241043
(13)2(22)41043
(13)22(24)1043
13(22)(24)1043
132(22)41043
1322(24)1043
(13)(22)(24)1043

{{
You need write code just to count the number of valid groups, rest is math,

Count all the valid two digit groups, [10 -> 26]

If v is the number of valid groups,
n is the length of the message,

Then number of ways we can decode the message with one group = nCn-2+1 = nCn-1
Then number of ways we can decode the message with two groups = nCn-4+2 = nCn-2
Then number of ways we can decode the message with "v" groups = nCn-2*v+v = nCn-v

Calculate nCn-v
}}