C Program to count node of tree | DS - IProgramX

Q.Write a C program which uses Binary search tree library and implements two more functions. 
Create(T, n) – inserts n nodes in the Binary search tree where the values are either accepted from user or randomly generated (use insert) 
Count(T) – returns the number of nodes in the tree 

Program

#include<stdio.h>
#include<stdlib.h>
struct node
{
int data;
struct node *left,*right;
};
int count =0;
struct node * createnode(struct node *newnode,int data)
{
newnode=malloc(sizeof(struct node));
newnode->data=data;
newnode->left= newnode->right = NULL;
return newnode;
}
void insert(struct node **root,int data)
{
struct node *newnode;
newnode=createnode(newnode,data);
if(*root==NULL)
*root=newnode;
else
{
struct node *temp=*root;
while(1)
{
if(data <= temp->data)
{
if(temp->left==NULL)
{
temp->left=newnode;
break;
}
temp=temp->left;
}
else
{
if(temp->right==NULL)
{
temp->right=newnode;
break;
}
temp=temp->right;
}
}
}
}
void createbst(struct node **root)
{
int n,i;
int data;
printf("\n\tENter the how many nodes ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("\n\tEnter data : ");
scanf("%d",&data);
insert(root,data);
}
}
int search(struct node *root, int data)
{
if(root==NULL)
printf("Empty Tree");
else
{
struct node *temp=root;
while(1)
{
if(data <= temp->data)
{
if(temp->left==NULL)
return 0;
temp=temp->left;

if(temp->data == data)
return 1;

}
else
{
if(temp->right==NULL)
return 0;
temp=temp->right;
if(temp->data == data)
return 1;

}
}
}
}
void display(struct node *temp)
{
if(temp)
{
printf("%d\t",temp->data);
display(temp->left);
display(temp->right);
}
}
void countNodes(struct node *temp)
{
if(temp)
{
count++;
countNodes(temp->left);
countNodes(temp->right);
}
}
int menu()
{
int ch;
printf("\n\t0.Exit");
printf("\n\t1.Create tree");
printf("\n\t2.Display tree");
printf("\n\t3.Search a node");
printf("\n\t4.Count nodes in the tree");

printf("\n\tEnter your choice :");
scanf("%d",&ch);
return ch;
}

main()
{
struct node *root= NULL;
int ch;
while((ch=menu())!=0)
{
if(ch==1)
createbst(&root);
else
if(ch==2)
{
display(root);
printf("\n");
getchar();
}
else
if(ch==3)
{
int data;
printf("\n\tEnter data to be searched : ");
scanf("%d",&data);

if(search(root,data) == 1 )
printf("Node %d is present in tree\n",data);
else
printf("Node %d is not present in tree\n",data);
getchar();
}
else
if(ch==4)
{
countNodes(root);
printf("Nodes are : %d\n",count);
getchar();
}
}
}

Output:

        0.Exit
        1.Create tree
        2.Display tree
        3.Search a node
        4.Count nodes in the tree
        Enter your choice :1

        ENter the how many nodes 5

        Enter data : 2

        Enter data : 8

        Enter data : 5

        Enter data : 3

        Enter data : 0

        0.Exit
        1.Create tree
        2.Display tree
        3.Search a node
        4.Count nodes in the tree
        Enter your choice :3

        Enter data to be searched : 5
Node 5 is present in tree

        0.Exit
        1.Create tree
        2.Display tree
        3.Search a node
        4.Count nodes in the tree
        Enter your choice :4
Nodes are : 5

        0.Exit
        1.Create tree
        2.Display tree
        3.Search a node
        4.Count nodes in the tree
        Enter your choice :0