See below. On Thu, Apr 30, 2020 at 10:58 AM Roelof Wobben via Pharo-users < pharo-users@lists.pharo.org> wrote:
> and also not with this one : > > cardNumber := '4539 1488 0343 6467'. > oddSum := 0. > evenSum := 0. > nextIsOdd := false. > cardNumber reverseDo: [:digit | > digit = Character space ifFalse: [ > nextIsOdd > ifFalse: [oddSum := oddSum + (digit asString asInteger ) ] > ifTrue: [(((digit asString asInteger) * 2) > 9) > ifTrue: [evenSum := evenSum + ((digit asString asInteger) * 2) - 9 ] > ifFalse: [ evenSum := evenSum + (digit asString asInteger) * 2 ]]. > nextIsOdd := nextIsOdd not]]. > ^ evenSum > > > > > Op 30-4-2020 om 18:30 schreef Roelof Wobben: > > Op 30-4-2020 om 16:16 schreef Roelof Wobben: > >> nextIsOdd := true. > >> aString reverseDo: [:digit | > >> digit = Character space ifFalse: [ > >> nextIsOdd > >> ifTrue: [oddSum := ...] > >> ifFalse: [evenSum := ...]. > >> nextIsOdd := nextIsOdd not]]. > > > > hmm, > > > > Still no luck with this code : > > > > cardNumber := '4539 1488 0343 6467'. > > oddSum := 0. > > evenSum := 0. > > nextIsOdd := true. > > cardNumber reverseDo: [:digit | > > digit = Character space ifFalse: [ > > nextIsOdd > > ifTrue: [oddSum := oddSum + digit asInteger ] > > ifFalse: [evenSum := ((digit asInteger * 2) > 9) > > ifTrue: [evenSum + ((digit asInteger * 2) - 9) ] > > ifFalse: [ evenSum + (digit asInteger * 2) ]]. > > nextIsOdd := nextIsOdd not]]. > > ^ oddSum + evenSum > With the one change to use #digitValue instead of #asInteger (which answers the code point), the above example works. | evenSum oddSum | cardNumber := '4539 1488 0343 6467'. oddSum := evenSum := 0. nextIsOdd := true. cardNumber reverseDo: [:digit | digit = Character space ifFalse: [ nextIsOdd ifTrue: [oddSum := oddSum + digit digitValue ] ifFalse: [evenSum := ((digit digitValue * 2) > 9) ifTrue: [evenSum + ((digit digitValue * 2) - 9) ] ifFalse: [ evenSum + (digit digitValue * 2) ]]. nextIsOdd := nextIsOdd not]]. ^ oddSum + evenSum gives me 80 for the answer. A few (mostly) minor points: - I don't see why "reverse" is necessary. Of course if you use #do:, nextIsOdd needs to start with true. - repeating the "digit digitValue" or other variations adds clutter and reduces clarity - ((digit digitValue * 2) - 9) is not unreasonable, but could be simplified. What is the largest integer X such that 2xX<=9? > > > the answer schould be 57 where I get 1157 > > > > So some debugging to do > > > > >
