35 lines
777 B
Nim
35 lines
777 B
Nim
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import math, os
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randomize()
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const
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target = "METHINKS IT IS LIKE A WEASEL"
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alphabet = " ABCDEFGHIJLKLMNOPQRSTUVWXYZ"
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p = 0.05
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c = 100
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proc random(a: string): char = a[random(a.low..a.len)]
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proc negFitness(trial): int =
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for i in 0 .. <trial.len:
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if target[i] != trial[i]: inc result
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proc mutate(parent): string =
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result = ""
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for c in parent: result.add if random(1.0) < p: random(alphabet) else: c
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var parent = ""
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for i in 1..target.len: parent.add random(alphabet)
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var i = 0
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while parent != target:
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var copies = newSeq[string](c)
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for i in 0 .. <copies.len: copies[i] = mutate(parent)
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var best = copies[0]
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for i in 1 .. <copies.len:
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if negFitness(copies[i]) < negFitness(best): best = copies[i]
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parent = best
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echo i, " ", parent
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inc i
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