C Program to Search a Node in Binary Tree

This C Program search for a particular value in a binary tree.

Here is source code of the C Program to search for a particular value in a binary tree. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

```
/*
```

 * C Program to Search for a Particular Value in a Binary Tree

```
 *                  50
```
```
 *                  /\
```
```
 *                20  30
```

 *                /\

```
 *              70 80
```
```
 *              /\   \
```
```
 *            10 40  60
```
```
 */
```
```
 
```
```
#include <stdio.h>
```
```
#include <malloc.h>
```

/* Structure to create the binary tree */

```
 
```
```
struct btnode
```
```
{
```
```
    int value;
```
```
    struct btnode *l;
```
```
    struct btnode *r;
```
```
};
```
```
 
```
```
struct btnode *root = NULL;
```
```
int flag;
```
```
 
```
```
/* Function Prototypes */
```

void in_order_traversal(struct btnode *);

void in_order_search(struct btnode *,int);

```
struct btnode *newnode(int);
```
```
 
```
```
void main()
```
```
{ 
```

    /* Inserting elements in the binary tree */

```
    int search_val;
```
```
    root = newnode(50);
```
```
    root->l = newnode(20);
```
```
    root->r = newnode(30);
```
```
    root->l->l = newnode(70);
```
```
    root->l->r = newnode(80);
```
```
    root->l->l->l = newnode(10);
```
```
    root->l->l->r = newnode(40);
```
```
    root->l->r->r = newnode(60);
```
```
 
```

    printf("The elements of Binary tree are:");

```
    in_order_traversal(root);
```

    printf("Enter the value to be searched:");

```
    scanf("%d", &search_val);
```
```
    in_order_search(root, search_val);
```

    if (flag  =  =  0)    // flag to check if the element is present in the tree or not

```
    {
```

        printf("Element not present in the binary tree\n");

```
    }
```
```
}
```
```
 
```

/* Code to dynamically create new nodes */

```
struct btnode* newnode(int value)
```
```
{
```

    struct btnode *temp = (struct btnode *)malloc(sizeof(struct btnode));

```
    temp->value = value;
```
```
    temp->l = NULL;
```
```
    temp->r = NULL;
```
```
    return temp;
```
```
}
```
```
 
```

/* Code to display the elements of the binary tree */

```
 
```

void in_order_traversal(struct btnode *p)

```
{
```
```
    if (!p)
```
```
    {
```
```
        return;
```
```
    }
```
```
    in_order_traversal(p->l);
```
```
    printf("%d->", p->value);
```
```
    in_order_traversal(p->r);
```
```
}
```
```
 
```

/* Code to search for a particular element in the tree */

void in_order_search(struct btnode *p, int val)

```
{
```
```
    if (!p)
```
```
    {
```
```
        return;
```
```
    }
```
```
    in_order_search(p->l, val);
```
```
    if(p->value == val)
```
```
    {
```

        printf("\nElement present in the binary tree.\n");

```
        flag = 1;
```
```
    }
```
```
    in_order_search(p->r, val);
```
```
}
```

$ cc tree3.c
$ a.out
The elements of Binary tree are:10->70->40->20->80->60->50->30
Enter the value to be searched:60
Element present in the binary tree.
 
$ ./a.out
The elements of Binary tree are:10->70->40->20->80->60->50->30
Enter the value to be searched:99
Element not present in the binary tree