次のコード スニペットに問題があります。
using System;
using System.Collections.Generic;
using System.Text;
namespace trees_by_firas
{
class Program
{
static void Main(string[] args)
{
BinarySearchTree t = new BinarySearchTree();
t.insert(ref t.root, 10);
t.insert(ref t.root, 5);
t.insert(ref t.root, 6);
t.insert(ref t.root, 17);
t.insert(ref t.root, 2);
t.insert(ref t.root, 3);
BinarySearchTree.print(t.root);
Console.WriteLine("--------------------");
Console.WriteLine(t.FindMax());
Console.WriteLine(t.FindMin());
Console.WriteLine("--------------------");
Console.WriteLine(t.CountLeaves());
Console.WriteLine(t.CountNodes());
}
public class TreeNode
{
public int n;
public TreeNode _left;
public TreeNode _right;
public TreeNode(int n, TreeNode _left, TreeNode _right)
{
this.n = n;
this._left = _left;
this._right = _right;
}
public void DisplayNode()
{
Console.Write(n);
}
}
public class BinarySearchTree
{
public TreeNode root;
public BinarySearchTree()
{
root = null;
}
public void insert(ref TreeNode root, int x)
{
if (root == null)
{
root = new TreeNode(x, null, null);
}
else
if (x < root.n)
insert(ref root._left, x);
else
insert(ref root._right, x);
}
public int FindMin()
{
TreeNode current = root;
while (current._left != null)
current = current._left;
return current.n;
}
public int FindMax()
{
TreeNode current = root;
while (current._right != null)
current = current._right;
return current.n;
}
public TreeNode Find(int key)
{
TreeNode current = root;
while (current.n != key)
{
if (key < current.n)
current = current._left;
else
current = current._right;
if (current == null)
return null;
}
return current;
}
public void InOrder(ref TreeNode root)
{
if (root != null)
{
InOrder(ref root._left);
root.DisplayNode();
InOrder(ref root._right);
}
}
public int CountNodes()
{
int count = 1; // me!
if (root._left != null)
count += _left.CountNodes();
if (root._right != null)
count += _right.CountNodes();
return count;
}
public int CountLeaves()
{
int count = (root._left == null && root._right == null) ? 1 : 0;
if (root._left != null)
count += _left.CountLeaves();
if (root._right != null)
count += _right.CountLeaves();
return count;
}
public static void print(TreeNode root)
{
if (root != null)
{
print(root._left);
Console.WriteLine(root.n.ToString());
print(root._right);
}
}
}
}
}
次のエラーが表示されます。
Error 1 The name '_left' does not exist in the current context
// on the countnodes & countleaves
Error 2 The name '_right' does not exist in the current context
// on the countnodes & countleaves
これらのエラーを修正する方法について何か考えはありますか?