Compare strings in java and remove the part of string where they are identical

Search and read about Longest Common Subsequence, you can find efficient algorithms to find out the LCS of two input strings. After finding the LCS of the input strings, it is easy to manipulate the inputs. For example, in your case an LCS algorithm will find "SOFT" as the LCS of these two strings, then you might check whether the LCS is in the final part of the 2nd input and then remove it easily. I hope this idea helps.

An example LCS code in Java is here, try it: http://introcs.cs.princeton.edu/java/96optimization/LCS.java.html

Example scenario (pseudocode):

input1: "MISROSOFT";
input2: "APPLESOFT";

execute LCS(input1, input2);
store the result in lcs, now lcs = "SOFT";

iterate over the characters of input2,
if a character exists in lcs then remove it from input2.

As far as I understand, you want to remove any identical characters from the two strings. By identical I mean: same position and same character(code). I think the following linear complexity solution is the simplest:

 StringBuilder sb1 = new StringBuilder();
 StringBuilder sb2 = new StringBuilder(); //if you want to remove the identical char 
                                          //only from one string you don't need the 2nd sb
 char c;
 for(int i = 0; i<Math.min(s1.length,s2.length);i++){
     if((c = s1.charAt(i)) != s2.charAt(i)){
           sb1.append(c);
     }
 }
 return sb1.toString();

Try this algo- Create characters sequences of your first string and find it in second string.

performance -
Average case = (s1.length()-1)sq

public class SeqFind {
    public static String searchReplace(String s1,String s2) {
        String s3;
        boolean brk=false;
        for(int j=s1.length();j>0&&!brk;j--){
        for (int i = j-4; i > 0; i--) {
            String string = s1.substring( i,j);
            if(s2.contains(string)){
                System.out.println(s2+" - "+string+" "+s2.replace( string,""));
                brk=true;
                break;
            }
        }
    }
        return s3;      
    }
    public static void main(String[] args) {
        String s1 = "MICROSOFT";
        String s2 = "APPLESOFT";
        String s3 = searchReplace(s1,s2);
    }
}

Out put - APPLESOFT - SOFT - APPLE

   public class Match {

public static void main(String[] args)
{
    String s1="MICROSOFT";
    String s2="APPLESOFT";
    String[] s=new String[10];
    String s3;
    int j=0,k=0;
    for(int i=s2.length();i>0;i--)
    {
        s[j]=s2.substring(k,s2.length());
        if(s1.contains(s[j]))
        {
            s3=s2.substring(0,j);
                                 System.out.println(s1+""+s3);

            System.exit(0);

        }
        else
        {
            System.out.println("");
        }
                                j++;
                                k++;
    }


}

     }

I have edited the code you can give it an another try.

try this, not tested thou

 String s1 = "MICROSOFT";
         String s2 = "APPLESOFT";
         String s3="";
         for(int j=0; j<s1.length(); j++)
         {
             if(s1.charAt(j)==s2.charAt(j)){
                 s3+=s1.charAt(j);
             }
         }
         System.out.println(s1.replace(s3, " ") + " \n"+ s2.replace(s3, " "));

You should rather use StringBuffer if you want your String to be modified..

And in this case, you can have one extra StringBuffer, in which you can keep on appending non-matching character: -

    StringBuffer s1 = new StringBuffer("MICROSOFT");
    StringBuffer s2 = new StringBuffer("APPLESOFT");
    StringBuffer s3 = new StringBuffer();

    for(int j=0; j<s1.length(); j++)
    {
        char c1 = s1.charAt(j);
        char c2 = s2.charAt(j);

        if(c1==c2) {
            System.out.println("Match found!!!");
        } else {
            System.out.println("No match found!");
            s3.append(c1);
        }
    }
    s1 = s3;
    System.out.println(s1);    // Prints "MICRO"