Searching
Binary Search:
public class BinarySearch { public static void main(String[] args) { int arr[]={2,4,8,12,15}; int key=4; System.out.println("Index value is ="+binarySearch(arr,key)); } private static int binarySearch(int[] arr, int key) { int start=0; int end=arr.length-1; int mid=0; int index=-1; while (start < end) { mid=(start+end)/2; if (arr[mid]==key) { index=mid; break; } else if (key < arr[mid]) { end=mid; }else { start=mid; } } return index; } }