Merge pull request neetcode-gh#2650 from rmrt1n/110

Create 0110-balanced-binary-tree.rs

Author: tahsintunan

rust/0110-balanced-binary-tree.rs

@@ -0,0 +1,19 @@
+use std::rc::Rc;
+use std::cell::RefCell;
+impl Solution {
+    pub fn is_balanced(root: Option<Rc<RefCell<TreeNode>>>) -> bool {
+        fn dfs(root: Option<Rc<RefCell<TreeNode>>>) -> (bool, i32) {
+            match root {
+                None => (true, 0),
+                Some(node) => {
+                    let (l_balanced, l_max) = dfs(node.borrow().left.clone());
+                    let (r_balanced, r_max) = dfs(node.borrow().right.clone());
+                    let balanced = l_balanced && r_balanced && (l_max - r_max).abs() <= 1;
+                    (balanced, 1 + l_max.max(r_max))
+                }
+            }
+        }
+    
+        dfs(root).0
+    }
+}