create 94-Binary-Tree-Inorder-Traversal.kt

Jay-0331 · Dec 28, 2022 · 72ede76 · 72ede76
1 parent da0dca2
commit 72ede76
Showing 1 changed file with 37 additions and 0 deletions.
diff --git a/kotlin/94-Binary-Tree-Inorder-Traversal.kt b/kotlin/94-Binary-Tree-Inorder-Traversal.kt
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+//iterative version
+class Solution {
+ fun inorderTraversal(root: TreeNode?): List<Int> {
+ val res = ArrayList<Int>()
+ val stack = Stack<TreeNode>()
+
+ var node = root
+ while(node != null || !stack.isEmpty()){
+ while(node != null){
+ stack.push(node)
+ node = node.left
+ }
+ node = stack.pop()
+ res.add(node.`val`)
+ node = node.right
+ }
+
+ return res
+ }
+}
+
+//recursion version
+class Solution {
+ fun inorderTraversal(root: TreeNode?): List<Int> {
+ val res = ArrayList<Int>()
+
+ fun inOrder(node: TreeNode?) {
+ node?: return
+ inOrder(node.left)
+ res.add(node.`val`)
+ inOrder(node.right)
+ }
+
+ inOrder(root)
+ return res
+ }
+}