二叉搜索树

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#define maxn 1000
#define T char
using namespace std;
typedef struct btnode {
    T data;
    struct btnode *lchild;
    struct btnode *rchild;
}btnode;

btnode *root = NULL;
btnode *temp2 = NULL;
int leaf_number = 0;

btnode* newnode(T x) {
    btnode* p = (btnode* )malloc(sizeof(btnode));
    p->data = x;
    p->lchild = NULL;
    p->rchild = NULL;
    return p;
}

bool insert1(T x) {  //插入节点
    btnode *r = NULL, *q = NULL, *p = root;
    T k = x;
    while(p) {
        q = p;
        if(k < p->data) {
            p = p->lchild;
        }
        else if(k > p->data) {
            p = p->rchild;
        }
        else {
            cout << "duplicate!" << endl;
            return false;
        }
    }
    r = newnode(x);
    if(root) {
        if(k < q->data) {
            q->lchild = r;
        }
        else {
            q->rchild = r;
        }
    }
    else{
        root = r;
    }
    return true;
}

void exchange(btnode *bt) {   //交换左右子树。
    if(bt) {
        exchange(bt->lchild);
        exchange(bt->rchild);
    }
    if(bt == NULL) {
        return ;
    }
    temp2 = bt->lchild;
    bt->lchild = bt->rchild;
    bt->rchild = temp2;
}

void midorder(btnode *bt) {
    if(bt) {
        midorder(bt->lchild);
        cout << bt->data << ' ';
        midorder(bt->rchild);
    }
    if(bt == NULL) {
        return ;
    }
}

int total(btnode *bt) {  //求节点总数。感觉写的太缀余。
    int rnum = 0, lnum = 0;
    int num = 0;
    if(!bt) {
        return 0;
    }
    if(bt->lchild == NULL && bt->rchild == NULL) {
        leaf_number++;
        return 1;
    }
    if(bt->lchild == NULL && bt->rchild != NULL) {
       return rnum = total(bt->rchild) + 1;
    }
    if(bt->lchild != NULL && bt->rchild == NULL) {
        return lnum = total(bt->lchild) + 1;
    }
    if(bt->lchild != NULL && bt->rchild != NULL) {
       lnum = total(bt->lchild);
       rnum = total(bt->rchild);
      return num = lnum + rnum + 1;
    }
    return 0;//suseless
}
int height(btnode *t) {  //求树的高度。
    int lh = 0, rh = 0;
    if(!t) {
        return 0;
    }
    else{
        lh = height(t->lchild);
        rh = height(t->rchild);
        if(lh>rh){
            return lh+1;
        }
        else{
            return rh+1;
        }
    }
}

void preorder(btnode *bt) {
    if(bt == NULL) {
        return ;
    }
    if(bt) {
        cout << bt->data << ' ';
        preorder(bt->lchild);
        preorder(bt->rchild);
    }
}

int main()
{
    char str[maxn];
    int len = 0;
    gets(str);
    len = strlen(str);
    for(int i = 0; i < len; i++) {
        insert1(str[i]);
    }
    btnode *temp = root;
    cout << "preorder:  ";
    preorder(temp);
    cout << endl;
    cout << "midorder:  ";
    midorder(temp);
    cout << endl;
    exchange(temp);
    cout << "preorder:  ";
    preorder(temp);  cout << endl;
    cout << "midorder:  ";
    midorder(temp); cout << endl;
    int Total = total(temp);
    printf("The amount of the node: ");
    cout << Total << endl;
    printf("The height of the tree: ");
    int heigh = height(temp);
    cout << heigh << endl;
    printf("The leaf of the tree: ");
    cout << leaf_number << endl;
    return 0;
}
/******************************************************************
最近忙着备考，几乎很少写程序，完美结束考试，全心学习编程。
程序仅仅说明道理，如果想完善稍加改动即可！
测试数据：5382469170
********************************************************************/