4-5-9.cpp

#include<iostream>
using namespace std;
#define MAXSIZE 50
#define END 9999
typedef struct BNode{
    struct BNode* lchild;
    struct BNode* rchild;
    int key;
    int count;
}BNode,*BST;
int fun(BST T,int &minval,int &maxval){
    BST p=T;
    while(p->lchild)p=p->lchild;
    minval=p->key;
    p=T;
    while(p->rchild)p=p->rchild;
    maxval=p->key;
    return 0;
}
bool BST_Insert(BST &T,int x);
void InitBST(BST &T,int L[]);
void Print_BST(BST T,int tag);
BST BST_search(BST T,int value);
int main(){
    int L[MAXSIZE];
    int c;
    cin>>c;
    int i=0;
    for(i=0;i<MAXSIZE&&c!=END;i++){
        L[i]=c;
        cin>>c;
    }
    L[i]=c;
    BST T=NULL;
    InitBST(T,L);
    int minval,maxval;
    fun(T,minval,maxval);
    cout<<"min:"<<minval<<" max:"<<maxval<<endl;
    Print_BST(T,2);
    cout<<endl;
    return 0;
}
BST BST_search(BST T,int value){
    if(!T)return NULL;
    if(T->key>value)return BST_search(T->lchild,value);
    else if(T->key<value)return BST_search(T->rchild,value);
    else return T;
    return NULL;
}
bool BST_Insert(BST &T,int x){
    if(T){
        if(x<T->key)return BST_Insert(T->lchild,x);
        else if(x>T->key)return BST_Insert(T->rchild,x);
        else return false;
    }else{
        T=(BST)malloc(sizeof(BNode));
        T->key=x;
        T->lchild=NULL;
        T->rchild=NULL;
        return true;
    }
}
void InitBST(BST &T,int L[]){
    for(int i=0;L[i]!=END;i++){
        BST_Insert(T,L[i]);
    }
}
void Print_BST(BST T,int tag){
    if(!T)return ;
    if(tag==1)cout<<T->key<<" ";
    Print_BST(T->lchild,tag);
    if(tag==2)cout<<T->key<<" ";
    Print_BST(T->rchild,tag);
    if(tag==3)cout<<T->key<<" ";
    free(T);
}