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;
    }
}

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 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 java.util.Arrays;
 
public class QuickSortMain {
 
    private static int array[];
 
    public static void sort(int[] arr) {
 
        if (arr == null || arr.length == 0) {
            return;
        }
        array = arr;
        quickSort(0, array.length-1);
    }
 
    private static void quickSort(int left, int right) {
 
        int i = left;
        int j = right;
        // find pivot number, we will take it as mid
        int pivot = array[left+(right-left)/2];
 
        while (i <= j) {
            /**
             * In each iteration, we will increment left until we find element greater than pivot
             * We will decrement right until we find element less than pivot
             */
            while (array[i] < pivot) { i++; } while (array[j] > pivot) {
                j--;
            }
            if (i <= j) {
                exchange(i, j);
                //move index to next position on both sides
                i++;
                j--;
            }
        }
        // call quickSort() method recursively
        if (left < j)
            quickSort(left, j);
        if (i < right)
            quickSort(i, right);
    }
 
    private static void exchange(int i, int j) {
        int temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
 
    public static void main(String a[]){
        int[] input = {33,21,45,64,55,34,11,8,3,5,1};
        System.out.println("Before Sorting : ");
        System.out.println(Arrays.toString(input));
        sort(input);
        System.out.println("==================");
        System.out.println("After Sorting : ");
        System.out.println(Arrays.toString(array));
 
    }
}

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;
 
public void postMail( String recipients[ ], String subject, String message , String from) throws MessagingException
{
    boolean debug = false;
 
     //Set the host smtp address
     Properties props = new Properties();
     props.put("mail.smtp.host", "smtp.example.com");
 
    // create some properties and get the default Session
    Session session = Session.getDefaultInstance(props, null);
    session.setDebug(debug);
 
    // create a message
    Message msg = new MimeMessage(session);
 
    // set the from and to address
    InternetAddress addressFrom = new InternetAddress(from);
    msg.setFrom(addressFrom);
 
    InternetAddress[] addressTo = new InternetAddress[recipients.length]; 
    for (int i = 0; i < recipients.length; i++)
    {
        addressTo[i] = new InternetAddress(recipients[i]);
    }
    msg.setRecipients(Message.RecipientType.TO, addressTo);
    
 
    // Optional : You can also set your custom headers in the Email if you Want
    msg.addHeader("MyHeaderName", "myHeaderValue");
 
    // Setting the Subject and Content Type
    msg.setSubject(subject);
    msg.setContent(message, "text/plain");
    Transport.send(msg);
}

public static String addBinary(){
 // The two input Strings, containing the binary representation of the two values:
    String input0 = "1010";
    String input1 = "10";

    // Use as radix 2 because it's binary    
    int number0 = Integer.parseInt(input0, 2);
    int number1 = Integer.parseInt(input1, 2);

    int sum = number0 + number1;
    return Integer.toBinaryString(sum); //returns the answer as a binary value;
}