public BinaryTreeNode DeleteNode(BinaryTreeNode node, int val)
{
if (node == null || !node.val.HasValue)
{
return(null);
}
var value = node.val.Value;
if (value == val)
{
// 删除
// node为叶子节点 直接删除
if (node.left == null && node.right == null)
{
return(null);
}
// node为单子节点 子节点替代
if (node.left == null || node.right == null)
{
return(node.left ?? node.right);
}
var minNode = node.right;
while (minNode.left != null)
{
minNode = minNode.left;
}
var retNode = DeleteNode(node.right, minNode.val.Value);
node.right = retNode;
node.val = minNode.val.Value;
// node为双子节点
//BinaryTreeNode minNode = null;
//DeleteMinNode(node.right, ref minNode);
//if (minNode != null)
//{
// minNode.left = node.left;
// minNode.right = node.right;
//}
//return minNode;
}
else if (val < value)
{
if (node.left != null)
{
node.left = DeleteNode(node.left, val);
}
}
else
{
if (node.right != null)
{
node.right = DeleteNode(node.right, val);
}
}
return(node);
}
public BinaryTreeNode(int val, BinaryTreeNode left, BinaryTreeNode right)
{
this.val = val;
this.left = left;
this.right = right;
}