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24 lines
593 B
Smalltalk
24 lines
593 B
Smalltalk
"Fibonacci — recursive and array-memoised. Classic-corpus program for
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the Smalltalk-on-SX runtime."
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Object subclass: #Fibonacci
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instanceVariableNames: 'memo'!
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!Fibonacci methodsFor: 'init'!
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init memo := Array new: 100. ^ self! !
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!Fibonacci methodsFor: 'compute'!
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fib: n
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n < 2 ifTrue: [^ n].
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^ (self fib: n - 1) + (self fib: n - 2)!
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memoFib: n
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| cached |
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cached := memo at: n + 1.
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cached notNil ifTrue: [^ cached].
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cached := n < 2
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ifTrue: [n]
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ifFalse: [(self memoFib: n - 1) + (self memoFib: n - 2)].
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memo at: n + 1 put: cached.
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^ cached! !
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