Find the height of the binary tree, the number of nodes, traverse the binary tree

#include "stdio.h"
#include "malloc.h"
#include "math.h"
#include "string.h"
#define MAX 100
void exit (int);
/*--------------------*/



int count; /* Record the number of two-degree nodes in the binary tree */
int flag; /* Indicates whether the binary tree is an AVL tree */



/*--------------------*/



typedef struct node{
Char D;
struct node *lchild,*rchild;
}tnode;

/*-----Build-----Through the sequencing sequence and sequencing sequence */



void Mktree (char in[],int is,int ie,char post[],int posts,int poste,tnode **r)
{
int i;
if (Is>ie | | posts>poste)
*r=null;
else{
*r=malloc (sizeof (tnode));
(*r)->d=post[poste];
for (i=is;i<=ie;i++)
if (post[poste]==in) {
Mktree (in,is,i-1,post,posts,posts+i-is-1,& (*r)->lchild);
Mktree (in,i+1,ie,post,posts+i-is,poste-1,& (*r)->rchild);
Break
}
if (I>ie) {
printf ("Error:input contains an error!/n");
Exit (9);
}
}
}



/*-----Pre-order Traversal binary Tree-----*/



void preorder (Tnode *r)
{
if (r) {
printf ("%c", r->d);
Preorder (R->lchild);
Preorder (R->rchild);
}
}

/*-----Find the number of two-degree nodes in the binary tree-----*/



void BNode (Tnode *r)
{
if (r) {
if (r->lchild&&r->rchild)
count++;
BNode (R->lchild);
BNode (R->rchild);
}
}



/*-----Find the number of leaves in the binary tree-----*/



int leaf (tnode *r)
{
if (r==null)
return 0;
Else
if (r->lchild==null && r->rchild==null)
return 1;
Else
Return Leaf (r->lchild) + leaf (r->rchild);
}



/*-----Find the height of the leaf in the binary tree-----*/



int Height (tnode *r)
{
int h1,h2;
if (r==null)
return 0;
else{
H1=height (R->lchild);
H2=height (R->rchild);
if (ABS (H1-H2) >1)
flag=1;
Return 1+ (H1&GT;H2?H1:H2);
}
}

void Main ()
{
Tnode *r;
int height;
Char Post[max],in[max];
printf ("Input inorder and Postorder:/n");
Gets (in);
Gets (post);
Mktree (In,0,strlen (in) -1,post,0,strlen (POST) -1,&r);
printf ("The preorder is as follows:/n");
Preorder (R);
printf ("/nthere is%dletters in the tree./n", Leaf (r));
count=0;
BNode (R);
printf ("/nthere is%d binarynode in the tree./n", count);
flag=0;
Height=height (R);
printf ("/nthe height of the tree is%d/n", height);
if (flag==1)
printf ("/nthis bintree is not a avl!/n");
Else
printf ("/nthis Bintree is an avl!/n");
}