feat: midi

Author: jaspwr

competition/midi/.gitignore

@@ -0,0 +1,3 @@
+target
+*.mid
+*.midi

competition/synth/Cargo.lock competition/midi/Cargo.lockcompetition/synth/Cargo.lock renamed to competition/midi/Cargo.lock

@@ -4,9 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+midly = "0.5.3"
 rand = "0.9.1"
 rand_chacha = "0.9.0"
-flac-encoder = { git = "https://github.com/jaspwr/flac-encoder-rs", optional = true }
 
-[features]
-flac = ["dep:flac-encoder"]

competition/synth/Cargo.toml competition/midi/Cargo.tomlcompetition/synth/Cargo.toml renamed to competition/midi/Cargo.toml

@@ -0,0 +1,38 @@
+---toml
+[fuzz]
+exec = ["cargo", "run", "--release", "--", "generate"]
+env = {}
+
+[judge]
+exec = ["cargo", "run", "--release", "--quiet", "--", "validate"]
+
+[problem]
+points = 15
+difficulty = 2
+---
+
+# 🎹 MIDI
+Jane wrote a song and wants to build a synthesizer to play it. As individual notes on a synthesizer require separate oscillators, she needs to know the minimum number of oscillators required to play her song.
+
+Given a sequence of MIDI messages, determine maximum number of notes playing at the same time.
+
+## Input Format
+Each line represents a [MIDI message](https://www.mixagesoftware.com/en/midikit/help/HTML/midi_events.html). Each message contains a time in milliseconds, a MIDI opcode and a note number (ignore velocity). 
+* The two relevant MIDI opcodes are `0x8c` for note off and `0x9c` for note on.
+* The note number is an integer between 0 and 127.
+
+```
+0 156 60
+1000 140 60
+500 156 64
+2000 140 64
+2000 156 63
+2100 140 63
+```
+In this example, note 60 is played from 0 to 1000 ms, note 64 is played from 500 to 2000 ms and note 63 is played from 2000 ms to 2100 ms. 
+* The maximum number of notes playing at the same time is 2. 
+* If a note off and on event are sent on the same frame (such as in the case with notes 64 and 63), they do not overlap.
+* If a note is turned on again while it's already held or turned off while it's already released, that message does nothing.
+
+## Output Format
+Output a single integer, the maximum number of notes playing at the same time.