From b5e1c27db8c7d330ac13e43927b791b21d95de18 Mon Sep 17 00:00:00 2001
From: Reiner Herrmann <reiner@reiner-h.de>
Date: Wed, 31 Aug 2022 01:02:38 +0200
Subject: day10

---
 src/bin/day10.rs | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 src/bin/day10.rs

diff --git a/src/bin/day10.rs b/src/bin/day10.rs
new file mode 100644
index 0000000..562408b
--- /dev/null
+++ b/src/bin/day10.rs
@@ -0,0 +1,44 @@
+fn main() {
+    let input = [1,3,2,1,1,3,1,1,1,2];
+    println!("10a: {}", lookandsay_times(&input, 40).len());
+    println!("10b: {}", lookandsay_times(&input, 50).len());
+}
+
+fn lookandsay(input: &[u8]) -> Vec<u8> {
+    let mut say = Vec::new();
+
+    let mut count = 1;
+    let mut prev = input[0];
+    for n in input.iter().skip(1) {
+        if *n != prev {
+            say.push(count);
+            say.push(prev);
+            prev = *n;
+            count = 0;
+        }
+        count += 1;
+    }
+    say.push(count);
+    say.push(prev);
+
+    say
+}
+
+fn lookandsay_times(input: &[u8], times: u32) -> Vec<u8> {
+    let mut data = Vec::from(input);
+    for _ in 0..times {
+        data = lookandsay(&data);
+    }
+    data
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test() {
+        assert_eq!(lookandsay(&[1,1,1,2,2,1]), [3,1,2,2,1,1]);
+        assert_eq!(lookandsay_times(&[1], 5), [3,1,2,2,1,1]);
+    }
+}
-- 
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