#include<stdio.h>#include "fatal.h"struct TreeNode;typedef struct TreeNode *Position;typedef struct TreeNode *SearchTree;typedef int ElementType;SearchTree MakeEmpty(SearchTree T);Position Find(ElementType X,SearchTree T);Position FindMin(SearchTree T);Position FindMax(SearchTree T);SearchTree Insert(ElementType X,SearchTree T);SearchTree Delete(ElementType X,SearchTree T);ElementType Retrieve(Position P);struct TreeNode {    ElementType Element;    SearchTree left;    SearchTree right;};SearchTree MakeEmpty(SearchTree T){    if(T!=NULL)    {        MakeEmpty(T->left);        MakeEmpty(T->right);        free(T);    }    return NULL;}Position Find(ElementType X,SearchTree T){    if(T==NULL)        return NULL;    if(X<T->Element)        return Find(X,T->left);    else if(X>T->Element)        return Find(X,T->right);    else         return T;}Position FindMin(SearchTree T){    if(T==NULL)        return NULL;    if(T->left==NULL)        return T;    else        return FindMin(T->left);}Position FindMax(SearchTree T){    if(T==NULL)        return NULL;    else if(T->right==NULL)        return T;    else        return FindMax(T->right);}SearchTree Insert(ElementType X,SearchTree T){    if(T==NULL)    {        T=malloc(sizeof(struct TreeNode));        if(T==NULL)            FatalError("Out of space!!!");        else        {            T->Element=X;            T->left=T->right=NULL;        }    }    else if(X<T->Element)        T->left=Insert(X,T->left);    else if(X>T->Element)        T->right=Insert(X,T->right);    return T;}SearchTree Delete(ElementType X,SearchTree T){    Position TmpCell;    if(T==NULL)        Error("Error not found");    else if(X<T->Element)        T->left=Delete(X,T->left);    else if(X>T->Element)        T->right=Delete(X,T->right);    else if(T->left&&T->right)    {        TmpCell=FindMin(T->right);        T->Element=TmpCell->Element;        T->right=Delete(X,T->right);    }    else    {        TmpCell=T;        if(T->left==NULL)            T=T->right;        else if(T->right=NULL)            T=T->left;        free(TmpCell);    }    return T;}ElementType Retrieve(Position P){    if(P==NULL)        return -1;    else        return P->Element;}