Make your own puzzle using 9 squares and 8 counters (four of one colour, four of another). You can draw the square on a sheet of paper and use coins or other markers for the counters.
Start with your counters set up like this, leaving an empty space in the middle.
Your goal, in as few moves as possible, is to exchange all of the counters on the right with the counters on the left, so that you end up like this:
There are only two rules:
A counter can move into an adjacent empty space.
A counter can leapfrog over a single adjacent counter into an empty space.
Here's an example puzzle using 9 squares and 8 counters:
Start with the counters set up like this:
|1|2|3|
|4| |5|
|6|7|8|
Your goal is to exchange the counters on the right with the counters on the left, so that you end up like this:
|8|7|6|
| | |5|
|3|2|1|
You can refer to the numbers to easily understand the positions of the counters.
To solve the puzzle, you can follow these steps:
1. Move counter 5 to the empty space:
|1|2|3|
|4|5| |
|6|7|8|
Move 5 to the right.
2. Move counter 8 to the empty space:
|1|2|3|
|4|8|5|
|6|7| |
Move 8 up.
3. Move counter 7 to the empty space:
|1|2|3|
|4|8| |
|6|7|5|
Move 7 up.
4. Move counter 6 to the empty space:
|1|2|3|
|4| |8|
|6|7|5|
Move 6 left.
5. Move counter 4 to the empty space:
|1|2|3|
|4|6|8|
| |7|5|
Move 4 up.
6. Move counter 1 to the empty space:
|1|2|3|
| |6|8|
|4|7|5|
Move 1 right.
7. Move counter 2 to the empty space:
|1|2|3|
|6| |8|
|4|7|5|
Move 2 right.
8. Move counter 3 to the empty space:
|1|2|3|
|6|7|8|
|4| |5|
Move 3 down.
And voila! You have successfully exchanged all counters on the right with the counters on the left.
To solve the puzzle, follow these steps:
1. Start by moving one of the counters from the right side to the empty space in the middle. It doesn't matter which one you move.
- Situation: R _ R
- R: Counter of one color, _: Empty space
2. Move the counter adjacent to the empty space into the empty space, using the leapfrogging rule.
- Situation: _ R R
- R: Counter of one color, _: Empty space
3. Move one of the counters from the left side into the empty space.
- Situation: L R R
- L: Counter of another color, R: Counter of one color
4. Move the counter adjacent to the empty space into the empty space, using the leapfrogging rule.
- Situation: L _ R
- L: Counter of another color, _: Empty space
5. Move the counter adjacent to the empty space into the empty space.
- Situation: _ L R
- L: Counter of another color, _: Empty space
6. Move the counter from the right side into the empty space.
- Situation: L R _
- L: Counter of another color, R: Counter of one color, _: Empty space
7. Move the counter adjacent to the empty space into the empty space, using the leapfrogging rule.
- Situation: L _ R
- L: Counter of another color, _: Empty space, R: Counter of one color
8. Move one of the counters from the left side into the empty space.
- Situation: _ L R
- _: Empty space, L: Counter of another color, R: Counter of one color
9. Move the counter adjacent to the empty space into the empty space.
- Situation: R L _
- R: Counter of one color, L: Counter of another color, _: Empty space
10. Move the counter from the right side into the empty space.
- Situation: R _ L
- R: Counter of one color, _: Empty space, L: Counter of another color
11. Move the counter adjacent to the empty space into the empty space, using the leapfrogging rule.
- Situation: _ R L
- _: Empty space, R: Counter of one color, L: Counter of another color
12. Move the counter adjacent to the empty space into the empty space.
- Situation: L R _
- L: Counter of another color, R: Counter of one color, _: Empty space
Congratulations! You have successfully completed the puzzle, exchanging all the counters on the right with the counters on the left.