Binary Tree Inorder Traversal 2020-10-25 04:07
Solution 1
public static List<Integer> inorderTraversal(TreeNode root) {
List<Integer> res = new ArrayList<>();
Stack<TreeNode> stack = new Stack<>();
TreeNode cur = root;
while (cur != null || !stack.isEmpty()) {
if (cur != null) {
stack.push(cur);
cur = cur.left;
} else {
cur = stack.pop();
res.add(cur.val);
cur = cur.right;
}
}
return res;
}
| Runtime | Memory |
|---|---|
| 0 ms | 37.5 MB |
Solution 2
public static List<Integer> inorderTraversal(TreeNode root) {
List<Integer> res = new ArrayList<>();
if (root == null) {
return res;
}
if (root.left != null) {
res.addAll(inorderTraversal(root.left));
}
res.add(root.val);
if (root.right != null) {
res.addAll(inorderTraversal(root.right));
}
return res;
}
| Runtime | Memory |
|---|---|
| 0 ms | 36.5 MB |
EOF