Update 988-smallest-string-starting-from-leaf.js

Author: everthis

988-smallest-string-starting-from-leaf.js

@@ -39,3 +39,15 @@ function arrToStr(arr) {
   }
   return res
 }
+
+// another
+
+const smallestFromLeaf = function(root) {
+    if (!root) return ''
+    const char = String.fromCharCode(97 + root.val)
+    let left = smallestFromLeaf(root.left)
+    let right = smallestFromLeaf(root.right)
+    if (!left) return right + char
+    if (!right) return left + char
+    return (left < right ? left : right) + char
+};