public class UserService {

  private UserRepository userRepository;

  public UserService(UserRepository userRepository) {
    this.userRepository = userRepository;
  }

  public User getUserById(long id) {
    try {
      return userRepository.getUserById(id);
    } catch (Exception e) {
      // Log the exception here
      System.out.println("An error occurred while fetching the user: " + e.getMessage());
      return null;
    }
  }
}

public class UserRepository {

  public User getUserById(long id) throws Exception {
    // Database query to fetch the user
    if (id < 0) {
      throw new Exception("Invalid user id");
    }
    // Return the user object
    return new User(id, "John Doe");
  }
}

public class User {

  private long id;
  private String name;

  public User(long id, String name) {
    this.id = id;
    this.name = name;
  }

  public long getId() {
    return id;
  }

  public String getName() {
    return name;
  }
}

import java.util.Scanner;

/* In Heaven, the seed is tall and the oak small / It's input vital 
	* "The al-Madinatian," verse 236-37 
	* tinyurl.com/17snqkfv
	* email answer to [email protected]
	**/

public class Main
{
	public static void main(String args[])
	{
		int x = 0;
		int a, c, m = 10000;
		
		Scanner in = new Scanner(System.in);
		
		System.out.println("Please enter a seed, maximum 3000000:");
		x = in.nextInt();
		
		System.out.println("Please input a number, maximum 29:");
		a = in.nextInt();
		
		System.out.println("Please input a number, maximum 999999:");
		c = in.nextInt();
		
		char menu = 'y';
		while(menu != 'n')
		{
			x = (a*x + c) % m;
			
			System.out.println("The next number is " + x + "\nWould you like another? (y/n)");
			menu = in.next().charAt(0);
		}
	}
}

//██╗  ░█████╗░███╗░░░███╗  ██████╗░░█████╗░███████╗██████╗░░█████╗░██╗░░░░░██╗░░░██╗░██████╗
//██║  ██╔══██╗████╗░████║  ██╔══██╗██╔══██╗██╔════╝██╔══██╗██╔══██╗██║░░░░░██║░░░██║██╔════╝
//██║  ███████║██╔████╔██║  ██║░░██║███████║█████╗░░██║░░██║███████║██║░░░░░██║░░░██║╚█████╗░
//██║  ██╔══██║██║╚██╔╝██║  ██║░░██║██╔══██║██╔══╝░░██║░░██║██╔══██║██║░░░░░██║░░░██║░╚═══██╗
//██║  ██║░░██║██║░╚═╝░██║  ██████╔╝██║░░██║███████╗██████╔╝██║░░██║███████╗╚██████╔╝██████╔╝
//╚═╝  ╚═╝░░╚═╝╚═╝░░░░░╚═╝  ╚═════╝░╚═╝░░╚═╝╚══════╝╚═════╝░╚═╝░░╚═╝╚══════╝░╚═════╝░╚═════╝░

import java.util.Arrays;

public class LongestIncreasingSubsequence {
    public int lengthOfLIS(int[] nums) {
        if (nums.length == 0) {
            return 0;
        }

        int[] dp = new int[nums.length];
        Arrays.fill(dp, 1); // Initialize all elements in dp array to 1, as each element itself is a valid subsequence of length 1.

        int maxLength = 1; // Initialize the maximum length to 1, considering a single element as the sequence.

        for (int i = 1; i < nums.length; i++) {
            for (int j = 0; j < i; j++) {
                if (nums[i] > nums[j]) {
                    dp[i] = Math.max(dp[i], dp[j] + 1); // If nums[i] is greater than nums[j], update the longest subsequence length ending at i.
                }
            }
            maxLength = Math.max(maxLength, dp[i]); // Update the maximum length if needed.
        }

        return maxLength;
    }

    public static void main(String[] args) {
        LongestIncreasingSubsequence lis = new LongestIncreasingSubsequence();
        int[] nums = {10, 9, 2, 5, 3, 7, 101, 18};
        int result = lis.lengthOfLIS(nums);
        System.out.println("Length of the Longest Increasing Subsequence: " + result); // Output: 4
    }
}

public class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode head = new ListNode(0);
        ListNode handler = head;
        while(l1 != null && l2 != null) {
            if (l1.val <= l2.val) {
                handler.next = l1;
                l1 = l1.next;
            } else {
                handler.next = l2;
                l2 = l2.next;
            }
            handler = handler.next;
        }
        
        if (l1 != null) {
            handler.next = l1;
        } else if (l2 != null) {
            handler.next = l2;
        }
        
        return head.next;
    }
}

//sample code to write 100 random ints to a file, 1 per line

import java.io.PrintStream;
import java.io.IOException;
import java.io.File;

import java.util.Random;

public class WriteToFile {
    public static void main(String[] args) {
        try {
            PrintStream writer = new PrintStream(new File("randInts.txt"));
            Random r = new Random();
            final int LIMIT = 100;

            for (int i = 0; i < LIMIT; i++) {
                writer.println(r.nextInt());
            }
            writer.close();
        } catch (IOException e) {
            System.out.println("An error occured while trying to write to the file");
        }
    }
}

import static java.lang.System.*;
import java.util.Arrays;        

public class MergeSort{

private static int passCount;

public static void mergeSort(int[] list)
{
    passCount=0;
    mergeSort(list, 0, list.length);
}

private static void mergeSort(int[] list, int front, int back)  //O( Log N )
{
    int mid = (front+back)/2;
    if(mid==front) return;
    mergeSort(list, front, mid);
    mergeSort(list, mid, back);
    merge(list, front, back);

}

private static void merge(int[] list, int front, int back)  //O(N)
{
   int dif = back-front;
   int[] temp = new int[dif];
   int beg = front, mid = (front+back)/2;
   int saveMid = mid;
   int spot = 0;

   while(beg < saveMid && mid < back) {
      if(list[beg] < list[mid]) {
         temp[spot++] = list[beg++];
      } else {
         temp[spot++] = list[mid++];
      }
   }
   while(beg < saveMid)
      temp[spot++] = list[beg++];
   while(mid < back)
      temp[spot++] = list[mid++];
   for(int i = 0; i < back-front; i++) {
      list[front+i] = temp[i];
   }
    System.out.println("pass " + passCount++ + " " + Arrays.toString(list) + "\n");
  }
  
  
    public static void main(String args[])
    {
        mergeSort(new Comparable[]{ 9, 5, 3, 2 });
        System.out.println("\n");
        
        mergeSort(new Comparable[]{ 19, 52, 3, 2, 7, 21 });
        System.out.println("\n");
        
        mergeSort(new Comparable[]{ 68, 66, 11, 2, 42, 31});
        System.out.println("\n");
    }
  
 }