Copyright (c) James A. Storer Puzzle Contrast, Problem 4 (Go between the solutions for problems 1 and 2, and exchange pieces X and Y.) ###################################################################### Rectilinear Solution Rectilinear steps: 24 Straight-Line steps: 26 Unit steps: 38 ###################################################################### #0: B B A A Y X D D C C #1. Move X west 2 units: B B A A Y X D D C C #2. Move A south: B B Y X A A D D C C #3. Move B east 2 units: B B Y X A A D D C C #4. Move X on a path of 2 segments ending west: X B B Y A A D D C C #5. Move Y on a path of 2 segments ending north: X Y B B A A D D C C #6. Move A west 2 units: X Y B B A A D D C C #7. Move C north: X Y B B A A C C D D #8. Move D east 2 units: X Y B B A A C C D D #9. Move A south: X Y B B C C A A D D #10. Move C west 2 units: X Y B B C C A A D D #11. Move B south: X Y C C B B A A D D #12. Move Y east 2 units: X Y C C B B A A D D #13. Move X east 2 units: X Y C C B B A A D D #14. Move C north: C C X Y B B A A D D #15. Move B west 2 units: C C X Y B B A A D D #16. Move D north: C C X Y B B D D A A #17. Move A east 2 units: C C X Y B B D D A A #18. Move B south: C C X Y D D B B A A #19. Move D west 2 units: C C X Y D D B B A A #20. Move X south: C C Y D D X B B A A #21. Move Y south: C C D D X Y B B A A #22. Move C east 2 units: C C D D X Y B B A A #23. Move D north: D D C C X Y B B A A #24. Move X west 2 units: D D C C X Y B B A A