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-rw-r--r--day6/src/main.rs36
1 files changed, 36 insertions, 0 deletions
diff --git a/day6/src/main.rs b/day6/src/main.rs
new file mode 100644
index 0000000..46a148c
--- /dev/null
+++ b/day6/src/main.rs
@@ -0,0 +1,36 @@
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+fn main() -> std::io::Result<()> {
+ let file = File::open("input.txt")?;
+ let mut reader = BufReader::new(file);
+ let mut buffer = String::new();
+
+ reader.read_line(&mut buffer)?;
+
+ let mut lanternfishes: Vec<_> = buffer
+ .trim()
+ .split(',')
+ .map(|x| x.parse::<i16>().unwrap())
+ .collect::<Vec<i16>>();
+
+ for _ in 0..80 {
+ let mut n = 0;
+ for lanternfish in lanternfishes.iter_mut() {
+ if *lanternfish == 0 {
+ *lanternfish = 6;
+ n += 1;
+ } else {
+ *lanternfish -= 1;
+ }
+ }
+
+ for _ in 0..n {
+ lanternfishes.push(8);
+ }
+ }
+
+ println!("{}", lanternfishes.len());
+
+ Ok(())
+}