//-------------------------------------------------------------------------
// Class name: LetterCount
// Purpose: Given an character input count the letters and print the results
// Author: Ugo Posada Zabala
// Date: 01/09/2003
//-------------------------------------------------------------------------
 
public class letterCount {
    
    private int[] alphabet;
    
    public letterCount() {
        alphabet = new int[26];        	
    }    
    
    public void addLetter(char l) {
    	
        //Make sure that the word is in lower case
        String c = Character.toString( Character.toLowerCase(l) );        
 
        //According to the letter insert it in its appropiate position in 
        //the alpphabet array
	    if ( c.equals("a") ) {
	        alphabet[0] = alphabet[0] + 1;	 	
	    } else if ( c.equals("b") ) {
	        alphabet[1] = alphabet[1] + 1;
        } else if ( c.equals("c") ) {
	        alphabet[2] = alphabet[2] + 1;
	    } else if ( c.equals("d") ) {
	        alphabet[3] = alphabet[3] + 1;    
        } else if ( c.equals("e") ) {
	        alphabet[4] = alphabet[4] + 1;
	    } else if ( c.equals("f") ) {
	        alphabet[5] = alphabet[5] + 1;
	    } else if ( c.equals("g") ) {
	        alphabet[6] = alphabet[6] + 1;  
	    } else if ( c.equals("h") ) {
	        alphabet[7] = alphabet[7] + 1;
	    } else if ( c.equals("i") ) {
	        alphabet[8] = alphabet[8] + 1;
	    } else if ( c.equals("j") ) {
	        alphabet[9] = alphabet[9] + 1;
	    } else if ( c.equals("k") ) {
	        alphabet[10] = alphabet[10] + 1;
	    } else if ( c.equals("l") ) {
	        alphabet[11] = alphabet[11] + 1; 
	    } else if ( c.equals("m") ) {
	        alphabet[12] = alphabet[12] + 1; 
	    } else if ( c.equals("n") ) {
	        alphabet[13] = alphabet[13] + 1;
	    } else if ( c.equals("o") ) {
	        alphabet[14] = alphabet[14] + 1;
	    } else if ( c.equals("p") ) {
	        alphabet[15] = alphabet[15] + 1;
	    } else if ( c.equals("q") ) {
	        alphabet[16] = alphabet[16] + 1;
	    } else if ( c.equals("r") ) {
	        alphabet[17] = alphabet[17] + 1; 
	    } else if ( c.equals("s") ) {
	        alphabet[18] = alphabet[18] + 1;
	    } else if ( c.equals("t") ) {
	        alphabet[19] = alphabet[19] + 1;     
	    } else if ( c.equals("u") ) {
	        alphabet[20] = alphabet[20] + 1;
	    } else if ( c.equals("v") ) {
	        alphabet[21] = alphabet[21] + 1; 
	    } else if ( c.equals("w") ) {
	        alphabet[22] = alphabet[22] + 1;
	    } else if ( c.equals("x") ) {
	        alphabet[23] = alphabet[23] + 1;
	    } else if ( c.equals("y") ) {
	        alphabet[24] = alphabet[24] + 1;
	    } else if ( c.equals("z") ) {
	        alphabet[25] = alphabet[25] + 1;                              
	    } else {
	    	System.err.println("Unrecognized character: " + c );                    
        }
    }
    
    public void printResults() {
       System.out.println("");
       System.out.println("--------------------------");
       System.out.println("----- Letter counter -----");
       System.out.println("--------------------------");
       System.out.println("");
       System.out.println("Number of a: "+alphabet[0]);	
       System.out.println("Number of b: "+alphabet[1]);
       System.out.println("Number of c: "+alphabet[2]);
       System.out.println("Number of d: "+alphabet[3]);
       System.out.println("Number of e: "+alphabet[4]);
       System.out.println("Number of f: "+alphabet[5]);	
       System.out.println("Number of g: "+alphabet[6]);
       System.out.println("Number of h: "+alphabet[7]);
       System.out.println("Number of i: "+alphabet[8]);
       System.out.println("Number of j: "+alphabet[9]);       
       System.out.println("Number of k: "+alphabet[10]);	
       System.out.println("Number of l: "+alphabet[11]);
       System.out.println("Number of m: "+alphabet[12]);
       System.out.println("Number of n: "+alphabet[13]);
       System.out.println("Number of o: "+alphabet[14]);
       System.out.println("Number of p: "+alphabet[15]);	
       System.out.println("Number of q: "+alphabet[16]);
       System.out.println("Number of r: "+alphabet[17]);
       System.out.println("Number of s: "+alphabet[18]);
       System.out.println("Number of t: "+alphabet[19]);       
       System.out.println("Number of u: "+alphabet[20]);	
       System.out.println("Number of v: "+alphabet[21]);
       System.out.println("Number of w: "+alphabet[22]);
       System.out.println("Number of x: "+alphabet[23]);
       System.out.println("Number of y: "+alphabet[24]);
       System.out.println("Number of z: "+alphabet[25]);
       System.out.println("");
       System.out.println("--------------------------");
       System.out.println("");	
    }	
        
    public static void main(String[] args){
        
        //If there is no input exit the program
        if (args.length == 0) {
        	System.out.println("No word to process");
        	return;
        }	
        
        //Paste all string input into one
        String letters = "";        
        for ( int i=0; i < args.length; i++) letters = letters + args[i];
        
        letterCount myLetterCount = new letterCount(); 
        
        //get each character from the input and process it
        for (int i=0; i < letters.length(); i++) {
            char letter = letters.charAt(i);
            myLetterCount.addLetter(letter);    	
        }
        
        //Print the count
        myLetterCount.printResults();	
    }	
}

import java.util.*;
 
class MutableInteger
{
   int value;
   public MutableInteger() {}
   public MutableInteger(int initialValue) { value = initialValue; }
   public int inc() { return ++value; }
   public int getValue() { return value; }
   public void setValue( int v ) { value  = v; }
   public String toString() { return new Integer(value).toString(); }
}
 
class LetterFrequencyThingy
{
   Map letterMap = new HashMap();
   String defaultKey = "non-letters";
   
   public LetterFrequencyThingy()
   {
      String letters = "abcdefghijklmnopqrstuvwxyz";
      for( int i = 0; i < letters.length(); i++ )
         letterMap.put( letters.substring(i,i+1), new MutableInteger() );
      letterMap.put( defaultKey, new MutableInteger() );
   }
   
   public Map update( String s )
   {
      s = s.toLowerCase();
 
      for( int i = 0; i < s.length(); i++ )
      {
         String letter = s.substring(i,i+1);
 
         if( letterMap.containsKey(letter) )
            ((MutableInteger)letterMap.get(letter)).inc();
         else
            ((MutableInteger)letterMap.get(defaultKey)).inc();
      }
      return letterMap;
   }
   
   public static void main(String args[])
   {
      LetterFrequencyThingy thingy = new LetterFrequencyThingy();
      Map letterMap = thingy.update( "Let's just see how well this thing works, okay?" );
 
      Set keys = letterMap.keySet();
      Iterator i = keys.iterator();
      while( i.hasNext() )
      {
         Object key = i.next();
         System.out.println( key + " - " + letterMap.get(key) );
      }
   }
}