Find an Element In a Sorted Array Using Binary Search

binary serach

input:
6
5
1 3 5 7 9 11
output:
Success #stdin #stdout 0.1s 49484KB
element found


/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	static int eval(int[] a,int f,int s,int key){
		int mid=(f+s)/2;
		while(f<=s){
			if(a[mid]==key){
				return 1;
			}else if(key>a[mid]){
				return eval(a,mid+1,s,key);
			}else if(key<a[mid]){
				return eval(a,f,mid-1,key);
			}
		}
		return -1;
	}
	public static void main (String[] args) throws java.lang.Exception
	{
	   Scanner sc=new Scanner(System.in);
	   int s=sc.nextInt();
	   int key=sc.nextInt();
	   int arr[]=new int[s];
	   for(int i=0;i<s;i++){
	   	arr[i]=sc.nextInt();
	   }
	   int f=0;
	   int result=eval(arr,f,s-1,key);
	   if(result==1){
	   	System.out.println("element found");
	   }else{
	   	System.out.println("element not found");
	   }
	}
}