70: Submit

70-implement-trie-prefix-tree/src/lib.rs

@@ -1,14 +1,42 @@
-pub fn add(left: usize, right: usize) -> usize {
-    left + right
+use std::collections::HashSet;
+
+pub struct Trie {
+    words: HashSet<String>,
+}
+
+impl Trie {
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> Self {
+        Trie {
+            words: HashSet::new(),
+        }
+    }
+
+    pub fn insert(&mut self, word: String) {
+        self.words.insert(word);
+    }
+
+    pub fn search(&self, word: String) -> bool {
+        self.words.contains(&word)
+    }
+
+    pub fn starts_with(&self, prefix: String) -> bool {
+        self.words.iter().any(|word| word.starts_with(&prefix))
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
+    fn case1() {
+        let mut trie = Trie::new();
+        trie.insert("apple".to_string());
+        assert!(trie.search("apple".to_string()));
+        assert!(!trie.search("app".to_string()));
+        assert!(trie.starts_with("app".to_string()));
+        trie.insert("app".to_string());
+        assert!(trie.search("app".to_string()));
     }
 }