Otter AI - Phone Screen
Summary
During my phone screen with Otter AI, I was presented with a coding challenge focused on determining if a singer could perform a song based on their vocal range and the notes present in the song.
Full Experience
I had my phone screen with Otter AI, and the interviewer presented me with a problem to determine if a singer could perform a given song. The core of the problem involved comparing musical notes, which are defined by a pitch letter (C-B) and an octave number (0-7). The challenge was to ensure every note in the song fell within the singer's specified lowest and highest notes. The tricky part was implementing the custom comparison logic for notes, where a higher octave always means a higher note, and if octaves are the same, the pitch letter order determines which note is higher. Several examples and test cases were provided to clarify the requirements.
Interview Questions (1)
A new singer is looking for songs to perform. To be able to perform a song all the notes in the song must be within the singer's range, which is given by the lowest and highest notes the singer is able to sing.
A note is represented by:
- A letter for its pitch, ordered (lowest) C D E F G A B (highest)
- A number for its octave, ordered (lowest) 0 1 2 3 4 5 6 7 (highest)
For example, C5 is a note with pitch C and octave 5.
A note with a larger octave number is always higher than a note with a smaller octave number. If the octave number is the same, then a note with a later pitch letter is higher.
For example, here are some notes in order from lower to higher:
... G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 …
- A3 is higher than G3 because A comes after G in the ordering above
- C4 is higher than B3 because its octave number is larger
The lowest possible note is C0 and the highest possible note is B7.
You will be given as input a list of notes in a song, the lowest note the singer can sing, and the highest note the singer can sing. Write a function that returns whether the singer can sing the song.
Examples:
song1 = ["F4", "B4", "C5"]
singable(song1, "F4", "C5") => True
Every note in the song is between F4 and C5, so the singer can sing this song.
Note that B4 is higher than F4, since notes are ordered C D E F G A B
singable(song1, "A4", "C5") => False
F4 is lower than A4, so the singer cannot sing this song
song2 = ["C3", "E3", "G3", "C4", "E4", "G4", "C5"]
singable(song2, "B2", "C5") => True
singable(song2, "C3", "B4") => False
B2 is lower than C3. A note with a smaller octave number is always lower than a note with a larger octave number. Similarly, B4 is lower than C5
Additional input data:
song3 = [ "B4", "F5", "B5" ]
song4 = ["B4", "E4", "G4", "G4", "A4", "B4", "E4",
"B4", "E4", "G4", "G4", "A4", "C5", "B4",
"E5", "G4", "G4", "A4", "B4", "C5", "D5",
"C5", "B4", "C5", "E5", "D5", "C5", "C5",
"B4", "B4", "E5", "E4", "G4", "G4", "A4",
"B4", "B4", "B4", "C5", "E5", "A5", "E5",
"C5", "A4", "E5", "D5", "C5", "B4"]
song5 = [ "F4" ]
All test cases:
singable(song1, "F4", "C5") => True
singable(song1, "A4", "C5") => False
singable(song2, "B2", "C5") => True
singable(song2, "C3", "B4") => False
singable(song3, "B4", "B5") => True
singable(song3, "B4", "C5") => False
singable(song4, "D4", "A5") => True
singable(song4, "D4", "G5") => False
singable(song4, "D4", "C6") => True
singable(song4, "F4", "C6") => False
singable(song5, "D4", "E4") => False
Complexity Variables:
N = length of the song