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- NOTE ON THE KNIGHT'S TOURS IN THIS DIRECTORY
-
-
- 1. The programs in this directory demonstrate two things: the
- methods and strengths of recursion, and the folly and waste-
- fulness of brute force recursion as problems grow larger and
- more complex.
-
- 2. For background, read the article "on_recursion.txt" in this
- directory.
-
- 3. We thank old hand Terry Peterson for converting the original
- True Basic program demonstration of recursion into compiled A/C
- Basic, to prove that indeed that form of Basic can operate with
- recursive subroutine calls, passing arguments with each recursive
- call.
-
- Because the True Basic version does exactly the same thing
- as the compiled A/C Basic version, we didn't bother to include
- it.
-
- 4. Next, thanks to Doug Jones, who put together a recursive
- tour in C, found in the directory tour_c, along with source code.
- Doug's program runs fast as lightning, and solves all boards
- through 7 x 7 very quickly. But--it takes almost forever to solve
- an 8 x 8 board. Brute force fails on complex problems!
-
- Yet, with either of Jim Butterfield's programs, where you can
- intervene, you should solve an 8 x 8 board in an hour, with no
- previous practice.
-
- 5. Jim Butterfield's programs are written in Amiga Basic, for
- the interpreter. You must load Amiga Basic to use them. Both the
- programs Jim furnishes allow you to intervene when the program
- makes stupid moves. You can force it to back and fill in a
- corner, or to fill a single square which otherwise would prevent
- a solution. To pause his programs, press CTRL C. You'll get a
- "q" prompt. At it, enter the number of the move you want tried
- again. The programs will erase all subsequent moves, return to
- the move you designated, and try the next possible move.
-
- To quit Jim's programs, enter 0 (Zero) at the "q" prompt. You
- can't get out any other way!
-
- I converted Jim's programs, sent in token form, to ASCII, so
- you can read 'em in any editor or word processor.
-
- Dec. 13, 1988
-
- Dick Barnes
-