#include<stdio.h>
#include<conio.h>
struct node
{
int data;
struct node *left,*right;
};
typedef struct node tree;
void create( tree **p,int d)
{
  if(*p==NULL)
   {
    *p=(tree*)malloc(sizeof(tree));
    (*p)->data=d;
    (*p)->left=NULL;
    (*p)->right=NULL;
  }
   else
  {
    if(d<(*p)->data)
  {
  create(&((*p)->left),d);
 }
else
  {
   create(&((*p)->right),d);
   }
 }
}
void output(tree *p,int level)
{
int i;
if(p)
 {
 output(p->left,level+1);
 printf("\n");
 for(i=0;i<level;i++)
 printf(" ");
 printf("%d",p->data);
 output(p->right,level+1);
 }
}
  int search(tree *p,int data)
 {
 int flag=0;
  while(p!=NULL)
     {
     if(p->data==data)
       {
       flag=1;
       return(flag);
       }
       else
       if(data<p->data)
       {
       p=p->left;
       }
       else
       {
       p=p->right;
       }
     }
   return (flag);
 }
 void main()
 {
 tree *first=NULL;
  int flag;
 int number=0;
 char ch;int d;
 int data;
 clrscr();
  printf("\ninput choice 'b' to break:");
 ch=getchar();
 while(ch!='b')
 {
 fflush(stdin);
 printf("input information of the node:");
 scanf("%d",&data);
 fflush(stdin);
 printf("\ninput choice 'b' to break:");
 ch=getchar();
 }
 number--;
 printf("number of elements in the list is %d",number+1);
create(&first,d);
 printf("tree is:\n");
 output(first,1);
 fflush(stdin);
 printf("input the information of the node which we want to search:");
 scanf("%d",&data);
 flag=search(first,data);
 if(flag)
 {
 printf("search is successful");
 }
 else
 {
 printf("search is unsuccessful");
 }
 getch();
 }

#include <stdio.h>
#include <stdlib.h>
 
struct node {
  int data;
  struct node *left;
  struct node *right;
};
 
int search ( struct node *tree, int key )
{
  if ( tree == NULL ) {
    return 0;
  } else if ( key == tree->data ) {
    return 1;
  } else if ( key < tree->data ) {
    return search ( tree->left, key );
  } else {
    return search ( tree->right, key );
  }
}
 
struct node *insert ( struct node *tree, int key )
{
  if ( tree == NULL ) {
    tree = malloc ( sizeof *tree );
    if ( tree == NULL )
      return tree;
 
    tree->data = key;
    tree->left = tree->right = NULL;
  } else if ( key < tree->data ) {
    tree->left = insert ( tree->left, key );
  } else {
    tree->right = insert ( tree->right, key );
  }
 
  return tree;
}
 
void pretty_print ( struct node *tree, int level )
{
  if ( tree == NULL ) {
    printf ( "%*s~\n", level * 3, "" );
  } else {
    pretty_print ( tree->right, level + 1 );
    printf ( "%*s%d\n", level * 3, "", tree->data );
    pretty_print ( tree->left, level + 1 );
  }
}
 
void inorder_print ( struct node *tree )
{
  if ( tree == NULL )
    return;
 
  inorder_print ( tree->left );
  printf ( "%-4d", tree->data );
  inorder_print ( tree->right );
}
 
int main ( void )
{
  struct node *tree = NULL;
  int i, n = 0;
 
  for ( i = 0; i < 10; i++ )
    tree = insert ( tree, rand() % 100 );
 
  pretty_print ( tree, 0 );
  printf ( "\n---------------------------\n" );
 
  inorder_print ( tree );
  printf ( "\n---------------------------\n" );
 
  for ( i = 0; i < 100; i++ ) {
    if ( search ( tree, i ) != 0 ) {
      printf ( "%-4d", i );
      ++n;
    }
  }
 
  printf ( "\n%d numbers found", n );
  printf ( "\n---------------------------\n" );
 
  getchar();
 
  return 0;
}