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;
}