二叉查找树的Find,FindMin,FindMax的递归和非递归实现

typedef struct TreeNode *Position;
typedef struct TreeNode *SearchTree;

struct TreeNode{
    ElementType X;
    SearchTree Left;
    SearchTree Right;
};

//建立一颗空树的例程
SearchTree
MakeEmpty( SearchTree T )
{
    if( T != NULL )
    {//先做空儿子，在弄父亲
        MakeEmpty(T->Left);
        MakeEmpty(T->Right);
        free(T);
    }
    return NULL;//避免返回值的警告
}
//二叉查找树的Find操作（尾递归）
SearchTree
Find( SearchTree T, ElementType X )
{
    if( T == NULL )
        return NULL;
    if( T->Element > X )
        return Find( T->Left, X );
    else if( T->Element < X )
        return Find( T->Right, X );
    else
        return T;
}
//对二叉查找树FindMin操作(非递归实现，自创)
SearchTree
FindMin( SearchTree T )
{
    SearchTree Tmp;

    if(T == NULL )
        return NULL;//空树

    Tmp = T->Left;
    while( Tmp != NULL )
    {
        T = Tmp;
        Tmp = Tmp->Left;
    }
    return T->Element;
}
//FindMin操作非递归实现正解
SearchTree
FindMin( SearchTree T )
{
    if(T != NULL )
    {
        while( T->Left != NULL )
            T = T->Left;
    }
    return T;
}
//FindMin递归正解
SearchTree
FindMin( SearchTree T )
{
    if( T == NULL )
        return NULL;
    if( T->Left != NULL ){
        T = T->Left;
        return FindMin( T );
    }
    else
        return T;
}
//FindMax非递归
SearchTree
FindMax( SearchTree T )
{
    if( T == NULL )
        return NULL;
    while( T->Right != NULL )
    {
        T = T->Right;
    }
    return T;
}
//FindMax递归
SearchTree
FindMax( SearchTree T )
{
    if( T == NULL )
        return NULL;
    if( T->Right != NULL ){
        T = T->Right;
        return FindMax( T );
    }
    return T;
}
//FindMax递归超正解
SearchTree
FindMax( SearchTree T )
{
    if( T == NULL )
        return NULL;
    else
    if( T->Right == NULL )
        return T;
    else
        return FindMax( T->Right );
}

二叉树的节点儿子不多于两个，针对每个节点，且左子树所有数比节点小，右子树所有数比节点大