Dinesman's multiple-dwelling problem: Difference between revisions
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Small code enhancements, some comments on maintainability. |
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This program simply iterates through all numbers between 01234 and 43210 (base 5). To see whether this is a permutation worth testing, a binary mask is generated. If all 5 bits are set (31 decimal), this is a possible candidate. Then all ASCII digits of the generated number are converted back to numbers by subtracting the value of ASCII "0". Finally each of the conditions is tested. |
This program simply iterates through all numbers between 01234 and 43210 (base 5). To see whether this is a permutation worth testing, a binary mask is generated. If all 5 bits are set (31 decimal), this is a possible candidate. Then all ASCII digits of the generated number are converted back to numbers by subtracting the value of ASCII "0". Finally each of the conditions is tested. |
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All conditions are confined to a single word. The algorithm "as is" will work up to 10 floors. After that, we have to take into consideration that characters A-Z are used as digits. That will work up to 36 floors. |
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Although this is not ANS Forth, one should have little trouble converting it. |
Although this is not ANS Forth, one should have little trouble converting it. |
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then false \ nice try, no cigar.. |
then false \ nice try, no cigar.. |
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; |
; |
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( a --) |
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: .solution #floor 0 do i names i chars over + c@ 1+ emit cr loop drop ; |
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\ main routine |
\ main routine |
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: dinesman ( --) |
: dinesman ( --) |
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2932 194 do |
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2932 194 do i perm? if solution? if leave else drop then else drop then loop |
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i perm? if solution? if .solution leave else drop then else drop then |
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loop |
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; \ show the solution |
; \ show the solution |
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dinesman |
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dinesman</lang> |
dinesman</lang> |
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