C Program to Find Two Longest Distance Nodes using Inorder Traversal

This C Program find 2 nodes with longest distance and display using inorder traversal.

Here is source code of the C Program to find 2 nodes with longest distance and display using inorder traversal. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

```
/* 
```

 * C Program to Find 2 Nodes with Longest Distance and Display

```
 * using Inorder Traversal
```
```
 *             40
```
```
 *             /\
```
```
 *           20 60
```
```
 *           /\  \
```
```
 *         10 30  80
```
```
 *                 \
```
```
 *                  90
```
```
 */
```
```
#include <stdio.h>
```
```
#include <stdlib.h>
```
```
 
```
```
struct btnode
```
```
{
```
```
   int value;
```
```
   struct btnode *left, *right;
```
```
};
```
```
typedef struct btnode node;
```
```
 
```
```
/* function prototypes */
```
```
void insert(node *, node *);
```
```
void inorder(node *);
```
```
int  height(node *);
```
```
 
```
```
node *temp, *root = NULL;
```
```
 
```
```
void main()
```
```
{
```
```
    node *new = NULL ;
```
```
    int num  = 1;
```
```
 
```

    printf("Enter the elements of the tree(enter 0 to exit)\n");

```
    while (1)
```
```
    {
```
```
        scanf("%d",  &num);
```
```
        if (num == 0)
```
```
            break;
```
```
        new  =  malloc(sizeof(node));
```

        new->left  =  new->right  =  NULL;

```
        new->value  =  num;
```
```
        if (root  == NULL)
```
```
            root  =  new;
```
```
        else
```
```
        {
```
```
            insert(new, root);
```
```
        }
```
```
    }
```

    printf("elements in a tree in inorder are\n");

```
    inorder(root);
```
```
    height(root);
```
```
}
```
```
 
```

/* displaying nodes of a tree using inorder */

```
void inorder(node *root)
```
```
{
```
```
    if (root != NULL)
```
```
    {
```
```
        inorder(root->left);
```
```
        printf("%d -> ", root->value);
```
```
        inorder(root->right);
```
```
    }
```
```
}
```
```
 
```
```
/* inserting nodes into a tree */
```
```
void insert(node * new , node *root)
```
```
{
```
```
    if (new->value>root->value)
```
```
    {
```
```
        if (root->right  == NULL)
```
```
            root->right  =  new;
```
```
        else
```
```
            insert(new, root->right);
```
```
    }
```
```
    if (new->value<root->value)
```
```
    {
```
```
        if (root->left  == NULL)
```
```
            root->left = new;
```
```
        else
```
```
            insert(new, root->left);
```
```
    }
```
```
}
```
```
 
```
```
/* to find the longest path */
```
```
int height(node *temp)
```
```
{
```
```
    temp = root;
```
```
 
```
```
    if (temp  == NULL)
```
```
        printf("tree is empty\n");
```
```
    else
```
```
    {
```
```
        printf("\nlongest path is\n");
```
```
        while (temp->left != NULL)
```
```
        {
```
```
            if (temp->left == NULL)
```
```
                temp = temp->right;
```
```
            else
```
```
                temp = temp->left;
```
```
        }
```
```
        printf("%d ->", temp->value);
```
```
        temp = root;
```
```
        while (temp->right != NULL)
```
```
        {
```
```
              if (temp->right  == NULL)
```
```
                temp = temp->left;
```
```
            else
```
```
                temp = temp->right;
```
```
        }
```
```
        printf(" %d", temp->value);
```
```
    }
```
```
}
```

$ cc tree40.c
$ a.out
Enter the elements of the tree(enter 0 to exit)
40
20
30
50
60
80
90
0
elements in a tree in inorder are
20 -> 30 -> 40 -> 50 -> 60 -> 80 -> 90
longest path is
20 -> 90