1 files changed, 34 insertions, 0 deletions
diff --git a/2015/rs/code/ten/src/main.rs b/2015/rs/code/ten/src/main.rs
new file mode 100644
index 0000000..848c288
--- /dev/null
+++ b/2015/rs/code/ten/src/main.rs
@@ -0,0 +1,34 @@
+use std::fmt::Write;
+
+static INPUT: &str = "1113122113";
+
+fn main() {
+  let mut buf = INPUT.to_string();
+  for _ in 0..40 {
+    buf = part1(&buf);
+  }
+  println!("Final strlen @ 40: {}", buf.len());
+
+  for _ in 0..10 {
+    buf = part1(&buf);
+  }
+  println!("Final strlen @ 50: {}", buf.len());
+}
+
+fn part1(nums: &str) -> String {
+  let mut buf = String::with_capacity(nums.len() * 2); // worst-case
+  let mut chars = nums.chars();
+  let mut last = chars.next().unwrap();
+  let mut count = 1;
+  for char in chars {
+    if char == last {
+      count += 1;
+    } else {
+      let _ = write!(&mut buf, "{count}{last}");
+      last = char;
+      count = 1;
+    }
+  }
+  let _ = write!(&mut buf, "{count}{last}");
+  buf
+}