;; The first three lines of this file were inserted by DrRacket. They record metadata
;; about the language level of this file in a form that our tools can easily process.
#reader(lib "htdp-intermediate-reader.ss" "lang")((modname week6_tu_full) (read-case-sensitive #t) (teachpacks ((lib "image.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "image.ss" "teachpack" "htdp")))))
; Q1: What does the following call to (g 5) evaluate to?
(define (g x) (local [(define (g x) (* 4 x))] (g (+ x 1))))

(g 5)

; Three main ways to write templates for multiple complex arguments:
; 1)  Use the template for one arg, other arg(s) "along for the ride"
;     Example: append
; 2)  For two args of the same type, process them in "lock-step"
;     Example: list equality (see below)
; 3)  Consider "more complex interleaving" of the templates
;     Example: the intersect function from last week


; Q2: Write a function that takes two lists of numbers, and returns whether they
;     are identical.  You may assume the given lists have the same length.
;     Do not use the built-in "equal?" function

; lists-same : list-of-numbers list-of-numbers -> boolean
; returns whether two lists of the same length are identical
(define (lists-same lon1 lon2) 
  (cond[(empty? lon1) true]
       [(cons? lon1) 
        (and (= (first lon1) (first lon2))
                     (lists-same (rest lon1) (rest lon2)))]
   ))

(check-expect (lists-same empty empty) true)
(check-expect (lists-same (list 1 2 3) (list 1 2 3)) true)
(check-expect (lists-same (list 1 2 3) (list 1 2 4)) false)