Anagram.java

/*
 A word, phrase, or sentence formed from another by rearranging
its letters is knoen as anagrams. Thus the anagram of ten is net.
Write a method that check if a given two words are anagram or not
 */

package com.fsmvu.programmingproblemsolving;

import java.util.Arrays;

public class Anagram {

   public static boolean isAnagram(String w1, String w2){
        
        // check if they both have the same length
        if(w1.length()!=w2.length())
            return false;
        //create an array that represents all leters
        int[] balance= new int[26];
        // count the occurance number of each letter, if the occurance on both sides if equal,the result will be zero
        for(int i=0; i<w1.length();i++){
            balance[w1.charAt(i)-'a']++;
            balance[w2.charAt(i)-'a']--;   
        }
        //check if the balance is achieved
        for(int i=0; i<balance.length; i++){
            if(balance[0]!=0)
                return false;
        }
        
        return true;
    }

    /* second approach to the problem:
    create a char array for each word and sort them
     if sorted arrays are equal then they are anagram*/
    
    public static boolean isAnagram2(String w1, String w2){
        if(w1.length()!=w2.length()){
            return false;
        }
        char[] w1char=new char[w1.length()];
        char[] w2char=new char[w2.length()];
        //assign the string characters to char array
        for(int i=0; i<w1.length();i++){
            w1char[i]=w1.charAt(i);
        }
        for(int i=0; i<w2.length();i++){
            w2char[i]=w2.charAt(i);
        }
        Arrays.sort(w2char);
        Arrays.sort(w1char);
        //check the to array are equal after sorting 
        for(int i=0; i<w1char.length;i++){
            if(w1char[i]!=w2char[i]){
                return false;
            }
        }
        return true;
    }
  
}