hello-algo/codes/csharp/include/PrintUtil.cs

/**
 * File: PrintUtil.cs
 * Created Time: 2022-12-23
 * Author: haptear (haptear@hotmail.com)
 */

namespace hello_algo.include;

public class Trunk
{
    public Trunk? prev;
    public String str;

    public Trunk(Trunk? prev, String str)
    {
        this.prev = prev;
        this.str = str;
    }
};

public class PrintUtil
{
    /**
     * Print a linked list
     * @param head
     */
    public static void PrintLinkedList(ListNode head)
    {
        List<String> list = new();
        while (head != null)
        {
            list.Add(head.val.ToString());
            head = head.next;
        }
        Console.Write(String.Join(" -> ", list));
    }

    /**
     * The interface of the tree printer
     * This tree printer is borrowed from TECHIE DELIGHT
     * https://www.techiedelight.com/c-program-print-binary-tree/
     * @param root
     */
    public static void PrintTree(TreeNode? root)
    {
        PrintTree(root, null, false);
    }

    /**
     * Print a binary tree
     * @param root
     * @param prev
     * @param isLeft
     */
    public static void PrintTree(TreeNode? root, Trunk? prev, bool isLeft)
    {
        if (root == null)
        {
            return;
        }

        String prev_str = "    ";
        Trunk trunk = new Trunk(prev, prev_str);

        PrintTree(root.right, trunk, true);

        if (prev == null)
        {
            trunk.str = "———";
        }
        else if (isLeft)
        {
            trunk.str = "/———";
            prev_str = "   |";
        }
        else
        {
            trunk.str = "\\———";
            prev.str = prev_str;
        }

        showTrunks(trunk);
        Console.WriteLine(" " + root.val);

        if (prev != null)
        {
            prev.str = prev_str;
        }
        trunk.str = "   |";

        PrintTree(root.left, trunk, false);
    }

    /**
     * Helper function to print branches of the binary tree
     * @param p
     */
    public static void showTrunks(Trunk? p)
    {
        if (p == null)
        {
            return;
        }

        showTrunks(p.prev);
        Console.Write(p.str);
    }

    /**
     * Print a hash map
     * @param <K>
     * @param <V>
     * @param map
     */
    public static void printHashMap<K, V>(Dictionary<K, V> map) where K : notnull
    {
        foreach (var kv in map.Keys)
        {
            Console.WriteLine(kv.ToString() + " -> " + map[kv]?.ToString());
        }
    }
}