StacksQueues/Subsets/Java

Algorithm for finding permutations of subsets in lexicographic order, no recursion

Here are the steps:

To find permutations, in lexicographic order:

1. Sort the list of items and print this as the first permutation

2. Let i be the last index such that input[i] < input[i+1] (if no such index, we are done)

3. Let j be the last index such that input[i] < input[j]

4. Swap input[i] with input[j]

5. Reverse input[i+1] through input[input.length-1]

Example

Pass the flag "CHARLES"

First permutation is sorted: ACEHLRS

Second string is ACEHLSR

Third string is ACEHRLS

etc.