Towers of Hanoi: Difference between revisions
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(→{{header|Python}}: A variant which separates computation from display) |
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Move disk 1 from peg 2 to peg 3 |
Move disk 1 from peg 2 to peg 3 |
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</pre> |
</pre> |
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Or, separating the composition of the data from its display: |
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<lang python># hanoi :: Int -> String -> String -> String -> [(String, String)] |
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def hanoi(n, a, b, c): |
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def go(n, a, b, c): |
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p = n - 1 |
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return ( |
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go(p, a, c, b) + [(a, b)] + go(p, c, b, a) |
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) if 0 < n else [] |
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return go(n, a, b, c) |
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# TEST AND DISPLAY ----------------------------------- |
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# justifyRight :: Int -> Char -> String -> String |
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def justifyRight(n): |
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return lambda cFiller: lambda s: ( |
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((n * cFiller) + s)[-n:] |
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) |
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for step in map( |
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lambda xy: justifyRight(5)(' ')(xy[0]) + ' -> ' + xy[1], |
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hanoi(4, 'left', 'right', 'mid') |
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): |
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print(step) |
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</lang> |
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{{Out}} |
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<pre> left -> mid |
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left -> right |
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mid -> right |
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left -> mid |
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right -> left |
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right -> mid |
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left -> mid |
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left -> right |
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mid -> right |
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mid -> left |
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right -> left |
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mid -> right |
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left -> mid |
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left -> right |
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mid -> right</pre> |
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==={{libheader|VPython}}=== |
==={{libheader|VPython}}=== |
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