打印一棵二叉树

/**
 * 打印一棵二叉树
 * <p>
 * 中序遍历
 */
public class PrintBT {

    public static void printTree(Node head) {
        System.out.println("Binary Tree:");
        printInOrder(head, 0, "H", 17);
        System.out.println();
    }

    private static void printInOrder(Node head, int height, String to, int len) {
        if (head == null) {
            return;
        }
        printInOrder(head.right, height + 1, "v", len);
        String val = to + head.value + to;
        int lenM = val.length();
        int lenL = (len - lenM) / 2;
        int lenR = len - lenM - lenL;
        val = getSpace(lenL) + val + getSpace(lenR);
        System.out.println(getSpace(height * len) + val);
        printInOrder(head.left, height + 1, "^", len);
    }

    private static String getSpace(int num) {
        String space = " ";
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < num; i++) {
            builder.append(space);
        }
        return builder.toString();
    }

    /**
     * 二叉树结构
     */
    public static class Node {

        public int value;

        public Node left;

        public Node right;

        public Node(int data) {
            this.value = data;
        }

    }

}

/* 如有意见或建议，欢迎评论区留言；如发现代码有误，欢迎批评指正 */