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2016 Update

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Tina Müller 2016-12-05 22:15:40 +01:00
parent 948b86eafa
commit dcf5d15da3
7965 changed files with 139854 additions and 31002 deletions
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15
Task/Parsing-RPN-calculator-algorithm/Mathematica/parsing-rpn-calculator-algorithm.math
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@ -1,12 +1,9 @@
calc[rpn_] :=
Module[{tokens = StringSplit[rpn], steps},
steps = FoldList[
Switch[#2, _?DigitQ, Append[#, FromDigits[#2]], "^",
Append[#[[;; -3]], #[[-2]]^#[[-1]]], "*",
Append[#[[;; -3]], #[[-2]] #[[-1]]], "/",
Append[#[[;; -3]], #[[-2]]/#[[-1]]], "+",
Append[#[[;; -3]], #[[-2]] + #[[-1]]], "-",
Append[#[[;; -3]], #[[-2]] - #[[-1]]]] &, {}, tokens][[2 ;;]];
Grid[Transpose[{# <> ":" & /@ tokens,
Module[{tokens = StringSplit[rpn], s = "(" <> ToString@InputForm@# <> ")" &, op, steps},
op[o_, x_, y_] := ToExpression[s@x <> o <> s@y];
steps = FoldList[Switch[#2, _?DigitQ, Append[#, FromDigits[#2]],
_, Append[#[[;; -3]], op[#2, #[[-2]], #[[-1]]]]
] &, {}, tokens][[2 ;;]];
Grid[Transpose[{# <> ":" & /@ tokens,
StringRiffle[ToString[#, InputForm] & /@ #] & /@ steps}]]];
Print[calc["3 4 2 * 1 5 - 2 3 ^ ^ / +"]];