binarysearch.c

#include<stdio.h>

/*

    Time Complexity : O(logN)

    Space Complexity : O(1)

*/

int binarySearch(int a[], int n, int target) { // function to find element

    int low = 0, high = n - 1;

    while (low <= high) {

        int mid = (low + high) / 2;

        if (a[mid] < target) { 

            low = mid + 1;

        } else if (a[mid] == target) {

            return mid;

        } else { // a[mid] > target

            high = mid - 1;

        }

    }

    return -1; // if target element not found in array

}

int main() {

    int n = 5, found = -1, target = 6;

    int a[] = {1, 2, 3, 4, 5}; // array needs to be sorted in ascending order

    

    found = binarySearch(a, n, target);

    if (found == -1) {

        printf("Element not present in array\n");

    } else {

        printf("Element found at index %d\n", found);

    }

    return 0;

}