rs: add “1704. Determine if String Halves Are Alike”

Signed-off-by: Matej Focko <mfocko@redhat.com>

rs/determine-if-string-halves-are-alike.rs

@@ -0,0 +1,17 @@
+impl Solution {
+    fn get_vowels(s: &str) -> usize {
+        s.to_lowercase()
+            .chars()
+            .filter_map(|c| match c {
+                'a' | 'e' | 'i' | 'o' | 'u' => Some(c),
+                _ => None,
+            })
+            .count()
+    }
+
+    pub fn halves_are_alike(s: String) -> bool {
+        let (a, b) = s.split_at(s.len() / 2);
+
+        Solution::get_vowels(a) == Solution::get_vowels(b)
+    }
+}