;; The first three lines of this file were inserted by DrScheme. They record metadata
;; about the language level of this file in a form that our tools can easily process.
#reader(lib "htdp-intermediate-lambda-reader.ss" "lang")((modname gps1) (read-case-sensitive #t) (teachpacks ((lib "world.ss" "teachpack" "htdp") (lib "convert.ss" "teachpack" "htdp") (lib "guess-gui.ss" "teachpack" "htdp") (lib "guess.ss" "teachpack" "htdp") (lib "geocode.ss" "installed-teachpacks"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "world.ss" "teachpack" "htdp") (lib "convert.ss" "teachpack" "htdp") (lib "guess-gui.ss" "teachpack" "htdp") (lib "guess.ss" "teachpack" "htdp") (lib "geocode.ss" "installed-teachpacks")))))
;; Assignment: 1
;; Name: Kyle Maguire
;; ID: 3564
;; Name: Gail Terman
;; ID: 4133




|#               1               #|


;; A us-city is a (make-us-city Number Symbol Symbol Number Number)
(define-struct us-city (zip name state lat long))



;; Test and Example cities
(define testcity1
  (make-us-city 00000 'Teston 'Testachusetts 125 20))
(define testcity2
  (make-us-city 11111 'Testville 'Testesee 65 50))
(define testcity3
  (make-us-city 99999 'Testix 'Testazona 95 35))
(define stormwind
  (make-us-city 22222 'Stormwind 'Elwynn 80 20))
(define northshire
  (make-us-city 33333 'Northshire 'Elwynn 80 40))
(define phoenix
  (make-us-city 85009 'Phoenix 'Arizona 112.128368 33.456373))
(define boston
  (make-us-city 02115 'Boston 'Massachusetts 71.092215 42.342706))



|#               2               #|


;; to-posn: us-city -> Posn
;; Consumes a us-city and produces a posn of the location the city
;; would be on a 100 x 100 pixel map of the US
(define (to-posn city)
  (make-posn (* (- (us-city-lat city) 125) (- (/ 5 3)))
             (* (- (us-city-long city) 50) (- (/ 10 3 )))))

(check-expect (to-posn testcity1) (make-posn 0 100))
(check-expect (to-posn testcity2) (make-posn 100 0))
(check-expect (to-posn testcity3) (make-posn 50 50))
(check-expect (to-posn stormwind) (make-posn 75 100))



|#               3               #|


;; distance: us-city us-city -> Number
;; Consumes 2 us-cities and computes the distance between them
(define (distance city1 city2)
  (sqrt (+ (sqr (* (- (us-city-lat city1)
                           (us-city-lat city2)) 70))
           (sqr (* (- (us-city-long city1)
                           (us-city-long city2)) 55)))))

(check-expect (distance testcity1 stormwind) 3150)
(check-expect (distance testcity2 testcity2) 0)
(check-expect (distance stormwind northshire) 1100)
(check-within (distance boston phoenix) 2913 2914)



|#               4               #|


;; Some trip examples
(define trip1 (list testcity1 testcity2 testcity3))
(define trip2 (list phoenix boston stormwind northshire))
(define trip3 (list testcity3 testcity1 testcity2))
(define trip4 (list boston))



;; total-distance: [Listof us-city] -> Number
;; Consumes a list of us-cities and prodcues the distance
;; traveled visiting each city on the list in order
(define (total-distance loc)
  (local [(define (accum total loc)
            (cond
              [(empty? (rest loc)) total]
              [else (accum (+ (distance (first loc)
                                        (first (rest loc)))
                              total)
                           (rest loc))]))]
    (accum 0 loc)))

(check-within (total-distance trip1) 6768 6769)
(check-within (total-distance trip2) 5391 5392)
(check-within (total-distance trip3) 6768 6769)
(check-expect (total-distance trip4) 0)



|#               5               #|


;; all-states: [Listof us-city] -> [Listof Symbol]
;; Consumes a list of us-cities and produces a list of all
;; the states you would visit when visiting those cities,
;; in order
(define (all-states loc)
  (local [(define (accum lov loc)
            (cond
              [(empty? loc) lov]
              [(not (member (us-city-state (first loc)) lov))
               (accum (append lov (list (us-city-state (first loc))))
                      (rest loc))]
              [else (accum lov (rest loc))]))]
    (accum empty loc)))

(check-expect (all-states trip1) '(Testachusetts Testesee Testazona))
(check-expect (all-states trip2) '(Arizona Massachusetts Elwynn))
(check-expect (all-states trip3) '(Testazona Testachusetts Testesee))
(check-expect (all-states trip4) '(Massachusetts))