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@ -22,29 +22,32 @@ |
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current |
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(reduce (cdr list) reducer (reducer current (car list))))) |
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(define (first-last-combine current rest) |
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(define (combine list combiner) |
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(if |
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(null? current) |
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rest |
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(null? (car list)) |
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(cdr list) |
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(if |
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(null? rest) |
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current |
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(cons (car current) (cdr rest))))) |
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(null? (cdr list)) |
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(car list) |
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(combiner (car list) (cdr list))))) |
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(define (sum numbers) (reduce numbers + 0)) |
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(define (is-numeric-char char) (if (char-numeric? char) #t #f)) |
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(define (first-last list predicate) |
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(if |
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(null? list) |
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'() |
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(first-last-combine |
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(if |
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(predicate (car list)) |
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(cons (car list) (cons (car list) '())) |
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'()) |
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(first-last (cdr list) predicate)))) |
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(define (sum numbers) (reduce numbers + 0)) |
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(define (is-numeric-char char) (if (char-numeric? char) #t #f)) |
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(combine |
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(cons |
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(if |
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(predicate (car list)) |
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(cons (car list) (cons (car list) '())) |
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'()) |
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(first-last (cdr list) predicate)) |
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(lambda (current rest) |
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(cons (car current) (cdr rest)))))) |
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(define (solve-line line) |
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( |
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