//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 java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class SimpleWordCounter {
    
    public static void main(String[] args) {
        try {
            File f = new File("ciaFactBook2008.txt");
            Scanner sc;
            sc = new Scanner(f);
            // sc.useDelimiter("[^a-zA-Z']+");
            Map<String, Integer> wordCount = new TreeMap<String, Integer>();
            while(sc.hasNext()) {
                String word = sc.next();
                if(!wordCount.containsKey(word))
                    wordCount.put(word, 1);
                else
                    wordCount.put(word, wordCount.get(word) + 1);
            }
            
            // show results
            for(String word : wordCount.keySet())
                System.out.println(word + " " + wordCount.get(word));
            System.out.println(wordCount.size());
        }
        catch(IOException e) {
            System.out.println("Unable to read from file.");
        }
    }
}

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;
  }
}

public static void enu2ecefCov(GMatrix ecefCov, GMatrix enuCov, LLA refLLA) {
    double lambda = refLLA.longitude;
    double phi = refLLA.latitude;
    
    GMatrix R = new GMatrix(6, 6);
    GMatrix Rt = new GMatrix(6, 6);
    GMatrix tmp1 = new GMatrix(6, 6);
    GMatrix tmp2 = new GMatrix(6, 6);
    
    R.setElement(0, 0, -Math.sin(lambda));
    R.setElement(0, 1, -Math.sin(phi)*Math.cos(lambda));
    R.setElement(0, 2, Math.cos(phi)*Math.cos(lambda));
    R.setElement(1, 0, Math.cos(lambda));
    R.setElement(1, 1, -Math.sin(phi)*Math.sin(lambda));
    R.setElement(1, 2, Math.cos(phi)*Math.sin(lambda));
    R.setElement(2, 0, 0);
    R.setElement(2, 1, Math.cos(phi));
    R.setElement(2, 2, Math.sin(phi));
    R.setElement(3, 3, -Math.sin(lambda));
    R.setElement(3, 4, -Math.sin(phi)*Math.cos(lambda));
    R.setElement(3, 5, Math.cos(phi)*Math.cos(lambda));
    R.setElement(4, 3, Math.cos(lambda));
    R.setElement(4, 4, -Math.sin(phi)*Math.sin(lambda));
    R.setElement(4, 5, Math.cos(phi)*Math.sin(lambda));
    R.setElement(5, 3, 0);
    R.setElement(5, 4, Math.cos(phi));
    R.setElement(5, 5, Math.sin(phi));

    Rt.transpose(R);
    tmp1.mul(enuCov, R);
    ecefCov.mul(Rt, tmp1);
}

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");
    }
  
 }

public class Factorial
{
	public static void main(String[] args)
	{	final int NUM_FACTS = 100;
		for(int i = 0; i < NUM_FACTS; i++)
			System.out.println( i + "! is " + factorial(i));
	}
	
	public static int factorial(int n)
	{	int result = 1;
		for(int i = 2; i <= n; i++)
			result *= i;
		return result;
	}
}