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;
	}
}

import java.util.*;
 
public class HeapSortMain {
 
   public static void buildheap(int []arr) {
 
    /*
     * As last non leaf node will be at (arr.length-1)/2 
     * so we will start from this location for heapifying the elements
     * */
    for(int i=(arr.length-1)/2; i>=0; i--){
           heapify(arr,i,arr.length-1);
      }
   }
 
   public static void heapify(int[] arr, int i,int size) { 
      int left = 2*i+1;
      int right = 2*i+2;
      int max;
      if(left <= size && arr[left] > arr[i]){
         max=left;
      } else {
         max=i;
      }
 
      if(right <= size && arr[right] > arr[max]) {
         max=right;
      }
      // If max is not current node, exchange it with max of left and right child
      if(max!=i) {
         exchange(arr,i, max);
         heapify(arr, max,size);
      }
   }
 
   public static void exchange(int[] arr,int i, int j) {
        int t = arr[i];
        arr[i] = arr[j];
        arr[j] = t; 
   }
 
   public static int[] heapSort(int[] arr) {
 
      buildheap(arr);
      int sizeOfHeap=arr.length-1;
      for(int i=sizeOfHeap; i>0; i--) {
         exchange(arr,0, i);
         sizeOfHeap=sizeOfHeap-1;
         heapify(arr, 0,sizeOfHeap);
      }
      return arr;
   }
 
   public static void main(String[] args) {
      int[] arr={1,10,16,19,3,5};
      System.out.println("Before Heap Sort : ");
      System.out.println(Arrays.toString(arr));
      arr=heapSort(arr);
      System.out.println("=====================");
      System.out.println("After Heap Sort : ");
      System.out.println(Arrays.toString(arr));
   }
}

//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");
        }
    }
}

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;
}

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);
}

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.");
        }
    }
}