二叉树两节点距离

#include <stdio.h>

typedef int ElementType;

struct BinarySearchTreeNode
{
    ElementType Element;
    struct BinarySearchTreeNode *Left;
    struct BinarySearchTreeNode *Right;
};

//be careful with the names of the node and struct
struct BinarySearchTreeNode* BinaryTreeLCA(struct BinarySearchTreeNode* TreeRoot,struct BinarySearchTreeNode* TreeNode_1,struct BinarySearchTreeNode* TreeNode_2)
{
    if(TreeRoot==NULL || TreeRoot==TreeNode_1 || TreeRoot==TreeNode_2)
    {
        return TreeRoot;
    }
    
    struct BinarySearchTreeNode* NewLeft = BinaryTreeLCA(TreeRoot -> Left,TreeNode_1,TreeNode_2);
    struct BinarySearchTreeNode* NewRight = BinaryTreeLCA(TreeRoot -> Right,TreeNode_1,TreeNode_2);
    
    if(NewLeft && NewRight)
    {
        return TreeRoot;
    }
    
    return NewLeft == NULL ? NewRight : NewLeft;
}

int BinarySearchTreeNodeFindLevel(struct BinarySearchTreeNode *TreeRoot,struct BinarySearchTreeNode *NodeToBeFind)
{
    if(TreeRoot == NULL || NodeToBeFind == NULL)
    {
        return -1;
    }
    if(TreeRoot -> Element == NodeToBeFind -> Element)
    {
        return 0;
    }
    
    int Level = BinarySearchTreeNodeFindLevel(TreeRoot -> Left,NodeToBeFind);
    if(Level == -1)
    {
        Level = BinarySearchTreeNodeFindLevel(TreeRoot -> Right,NodeToBeFind);
    }
    if(Level != -1)
    {
        return (Level+1);
    }
    return -1;
}

int BinarySearchTreeNodeDistance(struct BinarySearchTreeNode* TreeRoot,struct BinarySearchTreeNode* TreeNode_1,struct BinarySearchTreeNode* TreeNode_2)
{
    struct BinarySearchTreeNode* TwoNodeLCA = BinaryTreeLCA(TreeRoot,TreeNode_1,TreeNode_2);
    
    int LCADistance = BinarySearchTreeNodeFindLevel(TreeRoot,TwoNodeLCA);
    int Node_1Distance = BinarySearchTreeNodeFindLevel(TreeRoot,TreeNode_1);
    int Node_2Distance = BinarySearchTreeNodeFindLevel(TreeRoot,TreeNode_2);
    
    return (Node_1Distance + Node_2Distance - 2 * LCADistance);
}

int main()
{
    //int result = BinarySearchTreeNodeDistance(TreeRoot,BinarySearchTreeNodeFind(-1,TreeRoot),BinarySearchTreeNodeFind(-1,TreeRoot));
    //printf("%d
",result);
    return 0;
}