Complicated ArrayList Function - Moving Between Fields Which A Player Can Perform Based On Game Rules

I have been working on this function and i can't get it to work. It's a little bit complicated so let me first explain what this is about:

1. As a little exam in my studies i have to program a halma console game with KI an stuff.

2. Everything is finished and works except for the Move-Calculation.

3. A Move is a Move from Field a to Field b which a player can perform in one round based on the game rules (Careful: We are not using the standard halma rules, we use different ones).

4. Class Move consists of the Starting Cell where the Figure before the Move stands and a target Cell where the figure will stay on at the Move end. It may include an Array of serveral Cells, the stop cells which the figure passes from start -> target since several jumps can be performed in one Move.

Valid Examples for Moves:

a -> b (From Field a to Field b)
d -> f through g,h,i (From Field d to Field f through the Field g,h,i

My Move Calculation where all possible Moves are calculated for a given figure consists of 2 parts. An expand() function which will generate all possible moves (works perfectly) and a jumpFix() function which isn't working properly.

Example:

After expand() I'm getting something like that:

a -> b
b -> c
c -> d
s -> t

This is however not finished, because the first 3 Moves are actually 1 Move. Because the player can Move from a -> d in one turn because those 3 are consecutive Move. The fixed Move would look like that:

a -> d through b,c

jumpFix() is also perfectly working for that situation, however there is one specific situation when it doesn't work. Let's say we have this situation.

a -> b
b -> c
c -> d
b -> e
e -> f
f -> g
s -> t

Then the only valid jumpFix() output would be:

a -> d through b,c
a -> g through b,e,f
s -> t

However i can not get it to work yet. Note: It definitely needs to be iterative, not rekursive else i would get an StackoverflowError.

This is my current Code of jumpFix():

Java Code:

/**
* Takes a look into all calculated moves and finds those which should be seen as one move, but are still considered to be more than one move (several jumps in one move)
*/

public static List<Move> jumpFix(List<Move> moves) {
Set<Move> result = new HashSet<Move>();
Set<Move> remove = new HashSet<Move>();
int lastSize = -1;
// repeat action until no moves could be merged
while (lastSize != remove.size()) {

[Code] ....

How to implement the special case where a Move splits into 2 or more branches and jumpFix() able to handle this case.