Recursive Binary Search

Binary Search Using Recursion

#include<stdio.h>

void binary_search(int a[100], int low, int high, int key)

{

                int mid;

                if(low>high)

                {

                                printf("\nKey not found");

                                return;

                }

                mid = (low+high)/2;

                if(key == a[mid])

                {

                                printf("\nKey element is found at position = %d", mid);

                }

                else  if(key<a[mid])

                                binary_search(a, low, mid-1, key);

                else

                                binary_search(a, mid+1, high, key);

}

void main()

{

                int a[100], i, n, pos, key;

                printf("\nEnter value of n: ");

                scanf("%d", &n);

                printf("\nEnter the array elements: ");

                for(i=0; i<n; i++)

                                scanf("%d", &a[i]);

                printf("\nEnter key: ");

                scanf("%d", &key);

                binary_search(a, 0, n-1, key);

}

Output:

Enter value of n: 6

Enter the array elements: 11 22 33 44 55 66

Enter key: 55

Key element is found at position = 5

Enter value of n: 6

Enter the array elements: 11 22 33 44 55 66

Enter key: 88

Key is not found