// Iterative Solution : Time Complexity : O(LogN), Aux. Space : O(1)
import java.util.*;
import java.io.*;
class GFG
{
static int bSearch(int arr[], int n, int x)
{
int low = 0, high = n - 1;
while(low <= high)
{
int mid = (low + high) / 2;
if(arr[mid] == x)
return mid;
else if(arr[mid] > x)
high = mid - 1;
else
low = mid + 1;
}
return -1;
}
public static void main(String args[])
{
int arr[] = {10, 20, 30, 40, 50, 60}, n = 6;
int x = 25;
System.out.println(bSearch(arr, n, x)); // Output : -1
}
}
// Recursive Solution : Time Complexity : O(LogN), Aux. Space : O(logN)
import java.util.*;
import java.io.*;
class GFG
{
static int bSearch(int arr[], int low, int high, int x)
{
if(low > high)
return -1;
int mid = (low + high) / 2;
if(arr[mid] == x)
return mid;
else if(arr[mid] > x)
return bSearch(arr, low, mid - 1, x);
else
return bSearch(arr, mid + 1, high, x);
}
public static void main(String args[])
{
int arr[] = {10, 20, 30, 40, 50, 60, 70}, n = 7;
int x = 20;
System.out.println(bSearch(arr, 0, n - 1, x)); // Output : 1
}
}