my code is passed.I couldnot think of using ascii.My code is:

import java.io.; import java.util.; import java.text.; import java.math.; import java.util.regex.*; import java.util.Arrays; public class Solution {

public static int numberNeeded(String first, String second) {

    int flength=first.length();
    int slength=second.length();


   //System.out.println("flength is"+flength);
    //System.out.println("slength is"+slength);                 

    char f[]=first.toCharArray();
    char s[]=second.toCharArray();


    int count=0;

    int fcount=0;

    int scount=0;

    int ans=0;

    if(flength>slength)

    {

        for(int i=0;i<flength;i++)

        {

             for(int j=0;j<slength;j++)

             {

              if(f[i]==s[j])

              {

                  s[j]=0;



                  count++;

                  break;

             }

             }

        }
     // System.out.println("if part");
      ans=flength-count; 

    }




    else if(flength<slength)

    {



        for(int i=0;i<flength;i++)

        {

             for(int j=0;j<slength;j++)

             {

              if(f[i]==s[j])

              {

                  s[j]=0;



                  count++;

                  break;

             }

             }

        }
      //System.out.println("elseif part");
      ans=(flength+slength)-(2*count); 

    }








    else

    {

        for(int i=0;i<flength;i++)
        {
            for(int j=0;j<slength;j++)
            {
                if(f[i]==s[j])
                {
                    count++;
                    //f[i]=0;
                    s[j]=0;
                    break;
                }
            }
        }
       // System.out.println("else part");
        ans=(flength-count)+(slength-count);

    }




    return ans;



}



public static void main(String[] args) {

    Scanner in = new Scanner(System.in);

    String a = in.next();

    String b = in.next();

    System.out.println(numberNeeded(a, b));

}

} ....your solution is awesome.But what is the necessary of using ascii values.how can you think in this way?