Groovy中后序树遍历

class Node {
    int value
    Node left
    Node right
    
    Node(int value) {
        this.value = value
        this.left = null
        this.right = null
    }
}

// 后序遍历
def postorderTraversal(Node root) {
    if (root == null) {
        return
    }
    
    postorderTraversal(root.left)
    postorderTraversal(root.right)
    println(root.value)
}

// 创建二叉树
def createBinaryTree() {
    Node root = new Node(1)
    root.left = new Node(2)
    root.right = new Node(3)
    root.left.left = new Node(4)
    root.left.right = new Node(5)
    return root
}

// 测试后序遍历
def root = createBinaryTree()
postorderTraversal(root)