Searching Algorithm

To search an element in a given array, it can be done in two ways Linear search and Binary search.

Linear Search
Given an array arr[] of n elements, to search for a given element follow below steps :-

1. Start from the leftmost element of arr[] and one by one compare x with each element of arr[]
2. If x matches with an element, return the index.
3. If x doesn’t match with any of elements, return -1.

Binary Search
Search a sorted array by repeatedly dividing the search interval in half. Begin with an interval covering the whole array. If the value of the search key is less than the item in the middle of the interval, narrow the interval to the lower half. Otherwise narrow it to the upper half. Repeatedly check until the value is found or the interval is empty. Given an array arr[] of n elements, to search for a given element follow below steps :-

1. Compare x with the middle element.
2. If x matches with middle element, we return the mid index.
3. Else If x is greater than the mid element, then x can only lie in right half subarray after the mid element. So we recur for right half.
4. Else (x is smaller) recur for the left half.