David Gao kouddy

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kouddy / SICP 1.11.part 2

Created February 21, 2015 21:50

	> (f 1)
	1
	> (f 2)
	2
	> (f 3)
	4
	> (f 4)
	11
	> (f 5)
	25

kouddy / SICP 1.11.part 3

Created February 22, 2015 01:22

	(define (f-iter n)
	(f-iter-aux 2 1 0 n))

	(define (f-iter-aux a b c n)
	(if (= 0 n)
	c
	(f-iter-aux (+ a (* 2 b) (* 3 c))
	a
	b
	(- n 1))))

kouddy / SICP 1.12

Created February 22, 2015 02:56

	(define (pascal row col)
	(cond ((= col 1) 1)
	((= col row) 1)
	(else (+ (pascal (- row 1) (- col 1))
	(pascal (- row 1) col)))))

kouddy / SICP 1.15

Created February 22, 2015 03:44

	;;;(sine 12.15)
	(sine 12.15)
	(p (sine 4.05))
	(p (p (sine 1.35)))
	(p (p (p (sine 0.45))))
	(p (p (p (p (sine 0.15)))))
	(p (p (p (p (p (sine 0.05))))))
	(p (p (p (p (p 0.05)))))

kouddy / SICP 1.16

Created February 22, 2015 15:03

	(define (square x) (* x x))

	(define (even? n)
	(= (remainder n 2) 0))

	(define (fast-expt b n)
	(fast-expt-iter 1 b n))

	(define (fast-expt-iter a b n)
	(cond ((= n 0) a)

kouddy / SICP 1.18.part1

Last active August 29, 2015 14:15

	(define (double a) (* a 2))

	(define (halve a) (/ a 2))

	(define (even? n) (= (remainder n 2) 0))

	(define (fast-mult a b )
	(fast-mult-iter 0 a b))

	(define (fast-mult-iter a b n)

kouddy / SICP 1.18.part2

Created February 23, 2015 04:00

	;;; (fast-mult 3 15)
	(fast-mult-iter 0 3 15)
	(fast-mult-iter 3 3 14)
	(fast-mult-iter 3 6 7)
	(fast-mult-iter 9 6 6)
	(fast-mult-iter 9 12 3)
	(fast-mult-iter 21 12 2)
	(fast-mult-iter 21 24 1)
	(fast-mult-iter 45 24 0)
	45

kouddy / SICP 1.17.part1

Created February 24, 2015 01:45

	;;;(fast-expt 2 7)
	(* 2 (fast-expt 2 6))
	(* 2 (square (fast-expt 2 3)))
	(* 2 (square (* 2 (fast-expt 2 2))))
	(* 2 (square (* 2 (square (fast-expt 2 1)))))
	(* 2 (square (* 2 (square (* 2 (fast-expt 2 0))))))
	(* 2 (square (* 2 (square (* 2 1))))
	(* 2 (square (* 2 (square 2))))
	(* 2 (square (* 2 4)))
	(* 2 (square 8))

kouddy / SICP 1.17.part2

Created February 24, 2015 02:04

	;;;(fast-mult 2 7)
	(+ 2 (fast-mult 2 6))
	(+ 2 (* 2 (fast-mult 2 3)))
	(+ 2 (* 2 (+ 2 (fast-mult 2 2))))
	(+ 2 (* 2 (+ 2 (* 2 (fast-mult 2 1)))))
	(+ 2 (* 2 (+ 2 (* 2 (+ 2 (fast-mult 2 0))))))
	(+ 2 (* 2 (+ 2 (* 2 (+ 2 0)))))
	(+ 2 (* 2 (+ 2 (* 2 2))))
	(+ 2 (* 2 (+ 2 4)))
	(+ 2 (* 2 6))

kouddy / SICP 1.17.part3

Created February 24, 2015 02:05

	(define (double n) (* n 2))
	(define (halve n) (/ n 2))
	(define (even? n) (= (remainder n 2) 0))

	(define (fast-mult a b)
	(cond ((= b 0) 0)
	((even? b) (double (fast-mult a (halve b))))
	(else (+ a (fast-mult a (- b 1))))))