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// Iterative Code

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

class GFG
{
static int lastOcc(int arr[], int n, int x)
{
int low = 0, high = n - 1;

while(low <= high)
{
int mid = (low + high) / 2;

if(x > arr[mid])
low = mid + 1;

else if(x < arr[mid])
high = mid - 1;

else
{
if(mid == n - 1 || arr[mid + 1] != arr[mid])
return mid;

else
low = mid + 1;
}

}

return -1;
}

public static void main(String args[])
{
int arr[] = {5, 10, 10, 10, 10, 20, 20}, n = 7;

int x = 10;

System.out.println(lastOcc(arr, n, x));   // OUTPUT : 4
}

}

// Recursive Code

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

class GFG
{
static int lastOcc(int arr[], int low, int high, int x, int n)
{
if(low > high)
return -1;

int mid = (low + high) / 2;

if(x > arr[mid])
return lastOcc(arr, mid + 1, high, x, n);

else if(x < arr[mid])
return lastOcc(arr, low, mid - 1, x, n);

else
{
if(mid == n - 1 || arr[mid + 1] != arr[mid])
return mid;

else
return lastOcc(arr, mid + 1, high, x, n);
}
}

public static void main(String args[])
{
int arr[] = {5, 10, 10, 10, 10, 20, 20}, n = 7;

int x = 10;

System.out.println(lastOcc(arr, 0, n - 1, x, n));   // OUTPUT : 4
}

}