Initial data commit

Task/Evolutionary-algorithm/M2000-Interpreter/evolutionary-algorithm-1.m2000

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+Module WeaselAlgorithm {
+      Print "Evolutionary Algorithm"
+      \\ Weasel Algorithm
+      \\ Using dynamic array, which expand if no fitness change,
+      \\ and reduce to minimum when fitness changed
+      \\ Abandon strings when fitness change
+      \\ Also lambda function Mutate$ change when topscore=10, to change only one character
+      l$="ABCDEFGHIJKLMNOPQRSTUVWXYZ "
+      randomstring$=lambda$ l$ ->{
+            res$=""
+            For i=1 to 28: res$+=Mid$(L$,Random(1,27),1):next i
+            =res$
+      }
+      m$="METHINKS IT IS LIKE A WEASEL"
+      lm=len(m$)
+      fitness=lambda m$, lm  (this$)-> {
+            score=0 : For i=1 to lm {score+=If(mid$(m$,i,1)=mid$(this$, i, 1)->1,0)} : =score
+      }
+      Mutate$=lambda$ l$ (w$)-> {
+            a=random(1,28) : insert a, 1 w$=mid$(l$, random(1,27),1)
+            If random(3)=1 Then b=a:while b=a {b=random(1,28)} : insert b, 1 w$=mid$(l$, random(1,27),1)
+            =w$
+      }
+      Mutate1$=lambda$ l$ (w$)-> {
+            insert random(1,28), 1 w$=mid$(l$, random(1,27),1) : =w$
+      }
+      f$=randomstring$()
+      topscore=0
+      last=0
+      Pen 11 {Print "Fitness |Target:", @(16),m$, @(47),"|Total Strings"}
+      Print Over $(3,8), str$(topscore/28,"##0.0%"),"",$(0),f$, 0
+      count=0
+      gen=30
+      mut=0
+      {
+            last=0
+            Dim a$(1 to gen)<<mutate$(f$)
+            mut+=gen
+            oldscore=topscore
+            For i=1 to gen {
+                  topscore=max.data(topscore, fitness(a$(i)))
+                  If oldscore<topscore Then last=i:Exit
+            }
+            If last>0 Then {
+                  f$=a$(last) : gen=30 : If topscore=10 Then mutate$=mutate1$
+            } Else gen+=50
+            Print Over $(3,8), str$(topscore/28,"##0.0%"), "",$(0),f$, mut : refresh
+            count+=min(gen,i)
+            If topscore<28 Then loop
+      }
+      Print
+      Print "Results"
+      Print "I found this:"; a$(i)
+      Print "Total strings which evalute fitness:"; count
+      Print "Done"
+}
+WeaselAlgorithm