(count-w) Find how many “w” letters there are in a
word. Signature: count-w: string -> number.
(p7) Find the smallest power of 7 that is at least a given
number. (So find the smallest $k$ so that $7^k \ge \text{number}$.)
Signature: p7: number -> number.
(check-expect (p7 1) 0)
(check-expect (p7 7) 1)
(check-expect (p7 8) 2)
(check-expect (p7 49) 2)
(check-expect (p7 50) 3)(eyeball) Find how many pairs of consecutive zeros there are in a
number. Signature: eyeball: number -> number.
(check-expect (eyeball 0) 0)
(check-expect (eyeball 00) 0)
(check-expect (eyeball 1007008) 2)
(check-expect (eyeball 30008) 2)Explanations: the number 00 is really just 0, so there is only one zero. The number 30008 has two pairs of consecutive zeros: 3 00 08 and 30 00 8.
(no-z) Remove all z’s from a string. no-z: string -> string
(check-expect (no-z "whazzlez") "wale")(cq) Count how many times a given letter appears in a word.
cq: string(letter) string(word) -> number
One special case: when asked to count the number of “q” in a word,
only count “q” letters immediately followed by “u”.
(check-expect (cq "k" "kraken") 2)
(check-expect (cq "q" "queue q que") 2)(pink) Change every appearance of “pink” in the string to “blue”.
Signature: pink: string -> string.
(check-expect (pink "pink pink") "blue blue")Advanced: leave the first appearance alone.
(check-expect (pink-advanced "pink pink pink") "pink blue blue")