Hide
Problem D
Chord Detection 2
Accepted submissions to this problem will be granted a score of 3
This problem is a harder version of the problem Chord Detection. Instead of being given the names of the notes directly in the input, the input is instead given as a MIDI file, encoded in base 64. All inputs were created in the open-source online https://signal.vercel.app/edit. The sound file will play exactly three notes. There will be at least one moment in time when they were all pressed down at the same time. However, they may be of different length and starting times.
Input
A MIDI file in base 64 encoding.
Output
If the three notes in the input constitute a major chord, output x major, where $x$ is the base note of the chord.
Otherwise, output not a chord.
| Sample Input 1 | Sample Output 1 |
|---|---|
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 |
C major |
