Data commit

Task/Move-to-front-algorithm/Rust/move-to-front-algorithm.rust

@@ -0,0 +1,44 @@
+fn main() {
+    let examples = vec!["broood", "bananaaa", "hiphophiphop"];
+    for example in examples {
+        let encoded = encode(example);
+        let decoded = decode(&encoded);
+        println!(
+            "{} encodes to {:?} decodes to {}",
+            example, encoded, decoded
+        );
+    }
+}
+
+fn get_symbols() -> Vec<u8> {
+    (b'a'..b'z').collect()
+}
+
+fn encode(input: &str) -> Vec<usize> {
+    input
+        .as_bytes()
+        .iter()
+        .fold((Vec::new(), get_symbols()), |(mut o, mut s), x| {
+            let i = s.iter().position(|c| c == x).unwrap();
+            let c = s.remove(i);
+            s.insert(0, c);
+            o.push(i);
+            (o, s)
+        })
+        .0
+}
+
+fn decode(input: &[usize]) -> String {
+    input
+        .iter()
+        .fold((Vec::new(), get_symbols()), |(mut o, mut s), x| {
+            o.push(s[*x]);
+            let c = s.remove(*x);
+            s.insert(0, c);
+            (o, s)
+        })
+        .0
+        .into_iter()
+        .map(|c| c as char)
+        .collect()
+}