For 1.5

Understand how two variables in a for loop work and be able to use in-naturals.

1. Make an enumerate function to number the items in a list.

    (check-expect (enumerate (list "Pencils" "Pens" "Markers" "Erasers"))
                  (list "1. Pencils" "2. Pens" "3. Markers" "4. Erasers"))
   

2. The scs function takes in a list of numbers and a list of colors. It makes a list of solid squares by using the corresponding numbers and colors.

    (check-expect (scs (list 10 60 30) (list "orange" "blue" "pink"))
                  (list (square 10 "solid" "orange")
                        (square 60 "solid" "blue")
                        (square 30 "solid" "pink")))
   

3. The brc function takes in a list of color and makes bigger and bigger circles with those colors, starting with a radius of 20 and going up by 10 each time.

    (check-expect (brc (list "red" "orange" "yellow" "green"))
                  (list (circle 20 "solid" "red")
                        (circle 30 "solid" "orange")
                        (circle 40 "solid" "yellow")
                        (circle 50 "solid" "green")))
   

   Which gives:

   

4. Write a function to take in an image (the background) a list of m1 structs (see below) and output a list of images - the m1’s placed on the background.

    (define-struct m1 (x y p))
    (define ex1 (make-m1 50 75 pic:hacker))
    (define ex2 (make-m1 90 20 pic:calendar))
    (m1placer (empty-scene 200 100) (list ex1 ex2))
   

   Which gives: