Friday, 30 September 2016

Lab Program 10 Binary Search Tree 15CSL38 Data Structures in C Lab

Lab Program 10:

Design, Develop and Implement a menu driven Program in C for the following operations on Binary Search Tree (BST) of Integers
a. Create a BST of N Integers: 6, 9, 5, 2, 8, 15, 24, 14, 7, 8, 5, 2
b. Traverse the BST in Inorder, Preorder and Post Order
c. Search the BST for a given element (KEY) and report the appropriate messaged.
d. Exit











#include<stdio.h>
#include<stdlib.h> 

struct BST
{
            int data;
            struct BST *lchild;
            struct BST *rchild;
};
typedef struct BST * NODE;

NODE create()
{
            NODE temp;
            temp = (NODE) malloc(sizeof(struct BST));
            printf("\nEnter The value: ");
            scanf("%d", &temp->data);


            temp->lchild = NULL;
            temp->rchild = NULL;
            return temp;
}

void insert(NODE root, NODE newnode);
void inorder(NODE root);
void preorder(NODE root);
void postorder(NODE root);
void search(NODE root);

void insert(NODE root, NODE newnode)
{
    /*Note: if newnode->data ==  root->data it will be skipped. No duplicate nodes are allowed */
           
            if (newnode->data < root->data)
            {
                        if (root->lchild == NULL)
                                    root->lchild = newnode;
                        else
                                    insert(root->lchild, newnode);
            }
            if (newnode->data > root->data)
            {
                        if (root->rchild == NULL)
                                    root->rchild = newnode;
                        else
                                    insert(root->rchild, newnode);
            }
}


void search(NODE root)
{
            int key;
            NODE cur;
            if(root == NULL)
            {
                        printf("\nBST is empty.");
                        return;
            }
            printf("\nEnter Element to be searched: ");
            scanf("%d", &key);
            cur = root;
            while (cur != NULL)
            {
                        if (cur->data == key)
                        {
                                    printf("\nKey element is present in BST");
                                    return;
                        }
                        if (key < cur->data)
                                    cur = cur->lchild;
                        else
                                    cur = cur->rchild;
            }
            printf("\nKey element is not found in the BST");
}

void inorder(NODE root)
{
            if(root != NULL)
            {
                        inorder(root->lchild);
                        printf("%d ", root->data);
                        inorder(root->rchild);
            }
}

void preorder(NODE root)
{
            if (root != NULL)
            {
                        printf("%d ", root->data);
                        preorder(root->lchild);
                        preorder(root->rchild);
            }
}

void postorder(NODE root)
{
            if (root != NULL)
            {
                        postorder(root->lchild);
                        postorder(root->rchild);
                        printf("%d ", root->data);
            }
}


void main()
{
            int ch, key, val, i, n;
            NODE root = NULL, newnode;
            while(1)
            {
                        printf("\n~~~~BST MENU~~~~");
                        printf("\n1.Create a BST");
                        printf("\n2.Search");
                        printf("\n3.BST Traversals: ");
                        printf("\n4.Exit");
                        printf("\nEnter your choice: ");
                        scanf("%d", &ch);
                        switch(ch)
                        {
                                    case 1:             printf("\nEnter the number of elements: ");
                                                            scanf("%d", &n);
                                                            for(i=1;i<=n;i++)
                                                            {
                                                                        newnode = create();
                                                                        if (root == NULL)
                                                                                    root = newnode;
                                                                        else
                                                                                    insert(root, newnode);
                                                            }
                                                            break;
                                     case 2:             if (root == NULL)
                                                                       printf("\nTree Is Not Created");
                                                            else
                                                            {
                                                                        printf("\nThe Preorder display : ");
                                                                        preorder(root);
                                                                        printf("\nThe Inorder display : ");
                                                                        inorder(root);
                                                                        printf("\nThe Postorder display : ");
                                                                        postorder(root);
                                                            }

                                                            break;
                                     case 3:            search(root);
                                                            break;
                                     
                                    case 4:     exit(0);
                        }
            }
}

Output:
~~~~BST MENU~~~~
1.Create a BST
2.Search
3.BST Traversals:
4.Exit
Enter your choice: 1

Enter the number of elements: 12
Enter The value: 6
Enter The value: 9
Enter The value: 5
Enter The value: 2
Enter The value: 8
Enter The value: 15
Enter The value: 24
Enter The value: 14
Enter The value: 7
Enter The value: 8
Enter The value: 5
Enter The value: 2

~~~~BST MENU~~~~
1.Create a BST
2.Search
3.BST Traversals:
4.Exit
Enter your choice: 3

The Preorder display:           6          5          2          9          8          7          15        14        24
The Inorder display:             2          5          6          7          8          9          14        15        24
The Postorder display:         2          5          7          8          14        24        15        9          6

~~~~BST MENU~~~~
1.Create a BST
2.Search
3.BST Traversals:
4.Exit
Enter your choice: 2

Enter Element to be searched: 66
Key element is not found in the BST

~~~~BST MENU~~~~
1.Create a BST
2.Search
3.BST Traversals:
4.Exit
Enter your choice: 2

Enter Element to be searched: 14
Key element is present in BST

~~~~BST MENU~~~~
1.Create a BST
2.Search
3.BST Traversals:
4.Exit
Enter your choice: 4