Write a recursive version of an array-based linear search algorithm. Write a recursive version of a linked-list-based linear search algorithm. Solution // Recursive C program to implement linear search on array #include <stdio.h> //A linear search algorithm to find and return index of the searched element int array_linear_search_recursion(int numbers[], int length, int element, int index) { if(index<length) { if(numbers[index] == element) return index; else return array_linear_search_recursion(numbers, length, element, index+1); } else { // element not present return -1; } } int main() { int array[] = {44, 5, 78, 90, 111, 3, 45, 133, 54, 2, 3}; // input array int element = 5; //element to be searched int length = sizeof(array)/sizeof(array[0]); int result = array_linear_search_recursion(array, length, element, 0); //calling function to apply linear search recursively if(result == -1) printf(\"Element is not present in array\"); else printf(\"Element is present at index %d\", result); return 0; } // Recursive C program to implement linear search on linked list #include <stdio.h> #include <stdlib.h> /* Link list node */ struct node { int key; struct node* next; }; /* push a new node on the front of the list. */ void push(struct node** head, int new_element) { struct node* new_node = (struct node*) malloc(sizeof(struct node)); /* put in the key */ new_node->key = new_element; /* link the old list off the new node */ new_node->next = (*head); /* move the head to point to the new node */ (*head) = new_node; } /* Counts no. of nodes in linked list */ int search(struct node* head, int target) { // Base case if (head == NULL) return 0; // If key is present in current node, return true if (head->key == target) return 1; // Recursion for remaining list return search(head->next, target); } /* Drier program to test count function*/ int main() { /* create an empty list */ struct node* head = NULL; int target = 77; /* Use push() to construct below list 55->77->87->3->9 */ push(&head, 9); push(&head, 3); push(&head, 87); push(&head, 77); push(&head, 55); if(search(head, target) == 1) printf(\"Element is present in Linked list\ \"); else printf(\"Element is not not present in Linked list\ \"); return 0; } .

1. Write a recursive version of an array-based linear search algorithm.
Write a recursive version of a linked-list-based linear search algorithm.
Solution
// Recursive C program to implement linear search on array
#include <stdio.h>
//A linear search algorithm to find and return index of the searched element
int array_linear_search_recursion(int numbers[], int length, int element, int index)
{
if(index<length)
{
if(numbers[index] == element)
return index;
else
return array_linear_search_recursion(numbers, length, element, index+1);
}
else
{
// element not present
return -1;
}
}
int main()
{
int array[] = {44, 5, 78, 90, 111, 3, 45, 133, 54, 2, 3}; // input array
int element = 5; //element to be searched
int length = sizeof(array)/sizeof(array[0]);
int result = array_linear_search_recursion(array, length, element, 0); //calling function to apply
linear search recursively
if(result == -1)

2. printf("Element is not present in array");
else
printf("Element is present at index %d", result);
return 0;
}
// Recursive C program to implement linear search on linked list
#include <stdio.h>
#include <stdlib.h>
/* Link list node */
struct node
{
int key;
struct node* next;
};
/* push a new node on the front of the list. */
void push(struct node** head, int new_element)
{
struct node* new_node = (struct node*) malloc(sizeof(struct node));
/* put in the key */
new_node->key = new_element;
/* link the old list off the new node */
new_node->next = (*head);
/* move the head to point to the new node */
(*head) = new_node;
}
/* Counts no. of nodes in linked list */
int search(struct node* head, int target)
{
// Base case
if (head == NULL)
return 0;
// If key is present in current node, return true
if (head->key == target)
return 1;
// Recursion for remaining list
return search(head->next, target);
}

3. /* Drier program to test count function*/
int main()
{
/* create an empty list */
struct node* head = NULL;
int target = 77;
/* Use push() to construct below list
55->77->87->3->9 */
push(&head, 9);
push(&head, 3);
push(&head, 87);
push(&head, 77);
push(&head, 55);
if(search(head, target) == 1)
printf("Element is present in Linked list ");
else
printf("Element is not not present in Linked list ");
return 0;
}