Java代码实现构造一颗三叉链表表示的二叉树，实现输入叶子结点、 求二叉树中叶子结点个数、插入结点

以下是Java代码实现构造一颗三叉链表表示的二叉树，实现输入叶子结点、求二叉树中叶子结点个数、插入结点的示例代码：

class TreeNode {
    int data;
    TreeNode leftChild;
    TreeNode rightChild;
    TreeNode parent;
 
    public TreeNode(int data) {
        this.data = data;
        this.leftChild = null;
        this.rightChild = null;
        this.parent = null;
    }
}
 
class ThreeLinkBinaryTree {
    TreeNode root;
 
    public ThreeLinkBinaryTree(int data) {
        root = new TreeNode(data);
    }
 
    // 插入节点
    public void insert(TreeNode parent, boolean isLeft, int data) {
        TreeNode newNode = new TreeNode(data);
        if (isLeft) {
            parent.leftChild = newNode;
        } else {
            parent.rightChild = newNode;
        }
        newNode.parent = parent;
    }
 
    // 输入叶子节点
    public void inputLeafNodes(TreeNode node, Scanner scanner) {
        System.out.println("请输入节点 " + node.data + " 的左子节点：");
        int leftData = scanner.nextInt();
        if (leftData != -1) {
            TreeNode leftChild = new TreeNode(leftData);
            node.leftChild = leftChild;
            leftChild.parent = node;
            inputLeafNodes(leftChild, scanner);
        }
        System.out.println("请输入节点 " + node.data + " 的中间子节点：");
        int midData = scanner.nextInt();
        if (midData != -1) {
            TreeNode midChild = new TreeNode(midData);
            node.rightChild = midChild;
            midChild.parent = node;
            inputLeafNodes(midChild, scanner);
        }
        System.out.println("请输入节点 " + node.data + " 的右子节点：");
        int rightData = scanner.nextInt();
        if (rightData != -1) {
            TreeNode rightChild = new TreeNode(rightData);
            node.rightChild.rightChild = rightChild;
            rightChild.parent = node;
            inputLeafNodes(rightChild, scanner);
        }
    }
 
    // 求二叉树中叶子节点个数
    public int getLeafNodeCount(TreeNode node) {
        if (node == null) {
            return 0;
        }
        if (node.leftChild == null && node.rightChild == null) {
            return 1;
        } else {
            return getLeafNodeCount(node.leftChild) + getLeafNodeCount(node.rightChild);
        }
    }
}

使用示例：

Scanner scanner = new Scanner(System.in);
System.out.println("请输入根节点：");
int rootData = scanner.nextInt();
ThreeLinkBinaryTree tree = new ThreeLinkBinaryTree(rootData);
tree.inputLeafNodes(tree.root, scanner);
System.out.println("叶子节点个数为：" + tree.getLeafNodeCount(tree.root));
System.out.println("请输入要插入的节点：");
int data = scanner.nextInt();
tree.insert(tree.root, true, data);
System.out.println("叶子节点个数为：" + tree.getLeafNodeCount(tree.root));

注意：上述代码中的 `inputLeafNodes` 方法实现了输入三叉链表表示的二叉树的所有节点，其中输入 `-1` 表示该节点为空。