生成二叉排序树

#include <bits/stdc++.h>
using namespace std;
typedef int ElemType;

typedef struct Node{
    ElemType data;
    Node* lson;
    Node* rson;
}*Tree;

void preorder1(Tree T){
    if(T){
        printf("%d ",T->data);
        preorder1(T->lson);
        preorder1(T->rson);
    }
}

void inorder1(Tree T){
    if(T){
        inorder1(T->lson);
        printf("%d ",T->data);
        inorder1(T->rson);
    }
}
void preorder(Tree T){
    stack<Tree>s;
    while(T||!s.empty()){
        if(T){
            printf("%d ",T->data);
            s.push(T);
            T=T->lson;
        }
        else{
            T=s.top();
            s.pop();
            T=T->rson;
        }
    }
}

void inorder(Tree T){
    stack<Tree>s;
    while(T||!s.empty()){
        if(T){
            s.push(T);
            T=T->lson;
        }
        else{
            T=s.top();
            printf("%d ",T->data);
            s.pop();
            T=T->rson;
        }
    }
}

void postorder(Tree T){
    stack<Tree>s;
    Tree p=T,r=NULL;
    while(p||!s.empty()){

        if(p){
            //printf("%d ",p->data);
            s.push(p);
            p=p->lson;
        }
        else{
            p=s.top();
            if(p&&p->rson==r){
                printf("%d ",p->data);
                s.pop();
                r=p;
                p=NULL;
            }
            else if(p){
                p=p->rson;
                r=NULL;
            }
            
        }
    }
}

bool add(Tree &T,Tree pre,int x){
    if(!T){
        Node *p=new Node;
        p->data=x;
        p->lson=p->rson=NULL;
        if(x<pre->data)pre->lson=p;
        else pre->rson=p;
    }
    if(x<T->data){
        add(T->lson,T,x);
    }
    else if(x==T->data)return false;
    else{
        add(T->rson,T,x);
    }
}

Tree solve(int L[],int n){
    Tree T=new Node;
    T->data=L[0];
    T->lson=T->rson=NULL;
    for(int i=1;i<n;i++){
        add(T,T,L[i]);
    }
    return T;
}


int main(){
    /*Node* v7 = new Node(7, NULL, NULL);
    Node* v1 = new Node(1, NULL, NULL);
    Node* v3 = new Node(3, NULL, NULL);
    Node* v2 = new Node(2, v1, v3);
    Node* v5 = new Node(5, NULL, NULL);
    Node* v6 = new Node(6, v5, v7);
    Node* v4 = new Node(4, v2, v6);
    Tre*/
    int L[10]={4,2,6,1,3,5,7};
    Tree T=solve(L,7);
    preorder(T);
    printf("
");
    inorder(T);
    printf("
");
    postorder(T);
}