Package g0101_0200.s0144_binary_tree_preorder_traversal

Class Solution

  • public class Solution
extends Object
    144 - Binary Tree Preorder Traversal.

    Easy

    Given the root of a binary tree, return the preorder traversal of its nodes’ values.

    Example 1:

    Input: root = [1,null,2,3]

    Output: [1,2,3]

    Example 2:

    Input: root = []

    Output: []

    Example 3:

    Input: root = [1]

    Output: [1]

    Example 4:

    Input: root = [1,2]

    Output: [1,2]

    Example 5:

    Input: root = [1,null,2]

    Output: [1,2]

    Constraints:

    • The number of nodes in the tree is in the range [0, 100].
    • -100 <= Node.val <= 100

    Follow up: Recursive solution is trivial, could you do it iteratively?

    • Constructor Detail

      • Solution

        public Solution()