All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Logic
ABCD (2) (Posted on 2008-03-07) Difficulty: 3 of 5
Place one of the four letters A, B, C or D in each of the blue-coloured cells. No letter can be horizontally or vertically adjacent to itself. The yellow-coloured tables above and to the left of the grid indicate how many times each letter appears in that column or row.

This is an extended version of ABCD.

A

3

2

0

2

2

2

0

3

1

B

2

1

3

0

0

1

3

0

2

C

1

2

1

3

2

3

1

2

1

A

B

C

D

0

1

2

1

2

0

2

1

2

2

0

4

3

4

4

1

0

3

2

2

2

3

3

2

1

1

0

4

4

2

3

3

1

No Solution Yet Submitted by Josie Faulkner    
Rating: 4.1667 (6 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
No Subject | Comment 3 of 20 |

I see Charlie found the same solution.  I had considered writing a program, but found it simple enough to do by trial and error. The key seems to be to start with the letters which occur most often in a given line (row or column), since there are limited possible placements.  It went a bit slowly at first, but when about half determined, the rest fell into place.

I normally prefer a computer solution, since (unless a bug) it will show a given (trial and error) solution is in fact unique; I'll look over Charlie's program.


  Posted by ed bottemiller on 2008-03-07 13:04:34
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (10)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information