二叉树的基础应用（建树+叶子数+深度+遍历 ）

#include <stdio.h>
#include <string.h>
#include <string>
#include <iostream>
#include <algorithm>

using namespace std;

typedef struct node
{
    char ch;
    struct node *ll;
    struct node *rr;
}Binode, *Bitree;

struct node *Creat_Bitree(struct node *root, char *s1, char *s2, int n)
{
    if(n<=0)
      return NULL;
    else
    {
        root=new Binode;
        root->ch=s1[0];

        int p = strchr(s2, s1[0])- s2;  //在s2中查找s1[0]元素
        root->ll= Creat_Bitree(root->ll, s1+1, s2, p);
        root->rr= Creat_Bitree(root->rr, s1+1+p, s2+1+p, n-1-p );
    }
    return root;
}

void Post_order(Bitree p)//后序遍历
{
    if(p)
    {
        Post_order(p->ll);
        Post_order(p->rr);
        printf("%c", p->ch);
    }
}

void In_order(Bitree p)//中序遍历
{
    if(p)
    {
        Post_order(p->ll);
        printf("%c", p->ch);
        Post_order(p->rr);
    }
}


void Pre_order(Bitree p)//先序遍历
{
    if(p)
    {
        printf("%c", p->ch);
        Post_order(p->ll);
        Post_order(p->rr);
    }
}

int Deep_Bitree(Bitree p)//求二叉树的深度
{
    int deep1, deep2;
    if(p==NULL)
      return 0;
    else
    {
        deep1=Deep_Bitree(p->ll);
        deep2=Deep_Bitree(p->rr);
        if(deep1 > deep2)
            return (deep1+1);
        else
            return (deep2+1);
    }
}


void Leaf_num(Bitree p, int *cnt) //计算叶子节点的个数
{
    if(p==NULL)
      return ;
    else
    {
        Leaf_num(p->ll, cnt );
        if(p->ll==NULL && p->rr==NULL )
        {
            (*cnt)++;
        }
        Leaf_num(p->rr, cnt );
    }
}

int main()
{
    char s1[200];
    char s2[200];

    scanf("%s", s1);
    scanf("%s", s2);
    int len =strlen(s1);

    Bitree root;
    Bitree p;

    root = Creat_Bitree(p, s1, s2, len );//root是已经建好二叉树的根节点


    p=root;
    Post_order(p); //从根点开始进行后序遍历
    printf("\n");

    p=root;
    int deep=Deep_Bitree(p);
    printf("%d\n", deep );

    int a=0;
    int *sum;
    sum=&a;

    p=root;
    Leaf_num(p, sum);
    printf("%d\n", *sum);

    return 0;
}