initial commit

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "pathshortener"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "pathshortener"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

src/main.rs

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+fn main() {
+    let directions = "ENWESWNS".to_string();
+    let res = shorten(directions);
+    println!("{:?}", res);
+}
+
+fn shorten(directions: String) -> String {
+    let characters: Vec<_> = directions.chars().collect();
+    let mut result = remove_doubles(&characters);
+    loop {
+        let out = remove_doubles(&result);
+        if out.len() == result.len() {
+            break;
+        } else {
+            result = out;
+        }
+    }
+    result.iter().map(|f| f.to_string()).collect()
+}
+
+fn remove_doubles(characters: &Vec<char>) -> Vec<char> {
+    let mut shortenable_map = vec![false; characters.len()];
+    let windows = characters.windows(2);
+
+    for (idx, window) in windows.enumerate() {
+        let shortenable = is_shortenable(window);
+        if shortenable {
+            shortenable_map[idx] = true;
+            shortenable_map[idx + 1] = true;
+        }
+    }
+
+    characters
+        .iter()
+        .enumerate()
+        .filter(|(idx, _)| !shortenable_map[*idx])
+        .map(|(_, itm)| *itm)
+        .collect()
+}
+
+fn is_shortenable(chars: &[char]) -> bool {
+    match chars {
+        &['N', 'S'] => true,
+        &['S', 'N'] => true,
+        &['W', 'E'] => true,
+        &['E', 'W'] => true,
+        _ => false,
+    }
+}