/// <summary>
/// 在树上查找节点（非递归实现）
/// </summary>
/// <param name="request"></param>
/// <returns></returns>
public BinaryTreeNodeModel SelectLinkTree(int curr)
{
BinaryTreeNodeModel currNode = Root;
while (true)
{
if (curr > currNode.value)
{
currNode = currNode.childR;
}
else if (curr < currNode.value)
{
currNode = currNode.childL;
}
else
{
return(currNode);
}
//如果当前的父节点为空说明遍历到底了
if (currNode == null)
{
break;
}
}
return(null);
}
public BinaryTreeNodeModel(int value, BinaryTreeNodeModel parent)
{
this.value = value;
this.childL = null;
this.childR = null;
this.parent = parent;
}
/// <summary>
/// 查找当前节点左子树的最大值
/// </summary>
/// <param name="request"></param>
/// <returns></returns>
public BinaryTreeNodeModel FindLeftTreeMax(BinaryTreeNodeModel currNode)
{
BinaryTreeNodeModel node = currNode.childL;
if (node == null)
{
return(null);
}
while (true)
{
if (node.childR == null)
{
return(node);
}
node = node.childR;
}
}
/// <summary>
/// 在树上添加节点（递归实现）
/// </summary>
/// <param name="request"></param>
/// <returns></returns>
public object AddLinkTree(BinaryTreeNodeModel root, int curr)
{
if (curr >= root.value)
{
if (root.childR != null)
{
return(AddLinkTree(root.childR, curr));
}
BinaryTreeNodeModel child = new BinaryTreeNodeModel(curr, root);
root.childR = child;
}
else
{
if (root.childL != null)
{
return(AddLinkTree(root.childL, curr));
}
BinaryTreeNodeModel child = new BinaryTreeNodeModel(curr, root);
root.childL = child;
}
return(null);
}
/// <summary>
/// 在树上删除节点
/// </summary>
/// <param name="request"></param>
/// <returns></returns>
public string DeleteLinkTree(int curr)
{
BinaryTreeNodeModel node = SelectLinkTree(curr);
if (node == null)
{
return("该节点不存在");
}
if (node.childR == null && node.childL == null)
{
if (node == Root)
{
Root = null;
}
else
{
BinaryTreeNodeModel parent = node.parent;
if (parent.childL != null && parent.childL.value == node.value)
{
parent.childL = null;
}
else
{
parent.childR = null;
}
}
}
else if ((node.childR != null && node.childL == null) || (node.childR == null && node.childL != null))
{
if (node == Root)
{
Root = node.childR ?? node.childL;
}
else
{
BinaryTreeNodeModel parent = node.parent;
if (parent.childL != null && parent.childL.value == node.value)
{
parent.childL = node.childR ?? node.childL;
}
else
{
parent.childR = node.childR ?? node.childL;
}
}
}
else
{
BinaryTreeNodeModel childLMax = FindLeftTreeMax(Root);
BinaryTreeNodeModel temp;
BinaryTreeNodeModel parent;
if (node == Root)
{
temp = Root;
Root = childLMax;
childLMax.childR = temp.childR;
childLMax.childL = temp.childL;
}
else
{
parent = node.parent;
if (parent.childL.value == childLMax.value)
{
parent.childL = childLMax;
}
else
{
parent.childR = childLMax;
}
childLMax.childL = node.childL;
childLMax.childR = node.childR;
}
//将childLMax删除
parent = childLMax.parent;
if (parent.childL != null && parent.childL.value == childLMax.value)
{
parent.childL = null;
}
else
{
parent.childR = null;
}
}
return("删除成功");
}
