Petar Kapriš
a697f52405
To be noted: the drawing in exercise 1.14 is unfinished. I did it in a notebook, but haven't yet had the time to put it in a txt file.
171 lines
2 KiB
Scheme
171 lines
2 KiB
Scheme
#lang sicp
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(define (square x) (* x x))
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(define (smallest-divisor n)
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(find-divisor n 2))
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(define (find-divisor n test-divisor)
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(cond ((> (square test-divisor) n) n)
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((divides? test-divisor n) test-divisor)
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(else (find-divisor n (+ test-divisor 1)))))
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(define (divides? a b)
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(= (remainder b a) 0))
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(define (prime? n)
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(= n (smallest-divisor n)))
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(define (timed-prime-test n)
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(newline)
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(display n)
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(start-prime-test n (runtime)))
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(define (start-prime-test n start-time)
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(if (prime? n)
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(report-prime (- (runtime) start-time))))
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(define (report-prime elapsed-time)
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(display " *** ")
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(display elapsed-time))
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#| BEGIN (Write your solution here) |#
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(define (search-for-primes a b)
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(cond ((> a b) '())
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((not (even? a))
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(timed-prime-test a)
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(search-for-primes (+ a 2) b))
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(else (search-for-primes (+ a 1) b))))
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#| END |#
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;;;; TESTED OUTPUT
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;> (search-for-primes 1000 2000)
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;
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;1001
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;1003
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;1005
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;1007
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;1009 *** 1
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;1011
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;1013 *** 1
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;1015
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;1017
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;1019 *** 1
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;1021 *** 1
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;1023
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;1025
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;1027
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;1029
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;1031 *** 2
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;1033 *** 1
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;1035
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;1037
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;1039 *** 2
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;1041
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;1043
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;1045
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;> (search-for-primes 10000 10100)
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;
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;10001
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;10003
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;10005
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;10007 *** 7
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;10009 *** 5
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;10011
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;10013
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;10015
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;10017
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;10019
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;10021
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;10023
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;10025
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;10027
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;10029
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;10031
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;10033
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;10035
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;10037 *** 4
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;10039 *** 5
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;10041
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;10043
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;10045
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;10047
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;10049
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;10051
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;10053
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;10055
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;10057
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;10059
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;10061 *** 5
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;10063
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;10065
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;10067 *** 5
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;10069 *** 4
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;10071
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;10073
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;10075
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;10077
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;10079 *** 4
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;10081
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;10083
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;10085
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;10087
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;10089
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;10091 *** 5
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;10093 *** 9
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;10095
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;10097
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;10099 *** 7()
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;> (search-for-primes 100000 100100)
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;
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;100001
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;100003 *** 16
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;100005
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;100007
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;100009
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;100011
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;100013
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;100015
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;100017
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;100019 *** 15
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;100021
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;100023
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;100025
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;100027
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;100029
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;100031
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;100033
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;100035
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;100037
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;100039
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;100041
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;100043 *** 15
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;100045
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;100047
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;100049 *** 17
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;100051
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;100053
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;100055
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;100057 *** 16
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;100059
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;100061
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;100063
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;100065
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;100067
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;100069 *** 16
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;100071
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;100073
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;100075
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;100077
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;100079
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;100081
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;100083
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;100085
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;100087
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;100089
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;100091
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;100093
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;100095
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;100097
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;100099()
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