trie uses char slice instead of strings (#30)

Author: cameroncuster

examples/data_structures/trie.rs

@@ -17,10 +17,12 @@ fn main() {
 
         match command.as_str() {
             "insert" => {
-                trie.insert(&key);
+                let slice = key.chars().collect::<Vec<_>>();
+                trie.insert(&slice);
             }
             "find" => {
-                if trie.find(&key) > 0 {
+                let slice = key.chars().collect::<Vec<_>>();
+                if trie.find(&slice) > 0 {
                     println!("yes");
                 } else {
                     println!("no");

src/data_structures/trie.rs

@@ -22,12 +22,15 @@ impl Default for Node {
 /// use programming_team_code_rust::data_structures::trie::Trie;
 ///
 /// let mut trie = Trie::default();
-/// trie.insert("HELLO");
-/// trie.insert("HELLO");
-/// trie.insert("WORLD");
-/// assert_eq!(trie.find("HELLO"), 2);
-/// assert_eq!(trie.find("WORLD"), 1);
-/// assert_eq!(trie.find("WORLDS"), 0);
+/// let hello = vec!['H', 'E', 'L', 'L', 'O'];
+/// let world = vec!['W', 'O', 'R', 'L', 'D'];
+/// let hello_world = vec!['H', 'E', 'L', 'L', 'O', 'W', 'O', 'R', 'L', 'D'];
+/// trie.insert(&hello);
+/// trie.insert(&hello);
+/// trie.insert(&world);
+/// assert_eq!(trie.find(&hello), 2);
+/// assert_eq!(trie.find(&world), 1);
+/// assert_eq!(trie.find(&hello_world), 0);
 /// ```
 pub struct Trie {
     t: Vec<Node>,
@@ -47,9 +50,9 @@ impl Trie {
     /// # Complexity
     /// - Time: O(|s|)
     /// - Space: O(|s|)
-    pub fn insert(&mut self, s: &str) {
+    pub fn insert(&mut self, s: &[char]) {
         let mut v = 0;
-        for ch in s.chars() {
+        for &ch in s {
             let idx = (ch as u8 - FIRST_CHAR as u8) as usize;
             if self.t[v].next[idx].is_none() {
                 self.t[v].next[idx] = Some(self.t.len());
@@ -65,9 +68,9 @@ impl Trie {
     /// # Complexity
     /// - Time: O(|s|)
     /// - Space: O(1)
-    pub fn find(&self, s: &str) -> usize {
+    pub fn find(&self, s: &[char]) -> usize {
         let mut v = 0;
-        for ch in s.chars() {
+        for &ch in s {
             let idx = (ch as u8 - FIRST_CHAR as u8) as usize;
             if self.t[v].next[idx].is_none() {
                 return 0;