Deleting common characters in 2 different strings

Question

I am new to Xcode and iPhone developing. I am stuck in a problem.

I have two textFields and i want to compare these strings. If there is any common character then it should be omitted/deleted, and the new string is displayed in another textfield.

The common character can be at any location in the string and only one character is omitted at a time(in for loop).

Answer 1

I just wrote this! I havent found cases where it doesnt work! Tell me if it works for you!

 NSMutableString *shortString; //put your shortest string in here
    NSMutableString *longString; //put your longest string in here

    //index for characters to be removed in short string
    int characterIndexesShort[shortString.length], characterIndexesLong[longString.length];
    int commonCharactersShort = 0, commonCharactersLong = 0;
    int cut = 0;

    for(int i = 0; i < shortString.length; i++)
    {
        int oldLongCharCount = commonCharactersLong;
        char currentLetter = [shortString characterAtIndex:i];

        for(int j = 0; j < longString.length; j++)
        {
            if(currentLetter  == [longString characterAtIndex:j])
                characterIndexesLong[commonCharactersLong++] = j;
        }

        if(commonCharactersLong != oldLongCharCount)
            characterIndexesShort[commonCharactersShort++] = i;
    }
    //At this point you will have arrays containing the indexes of the common characters in both strings


    for(int i = 0; i < commonCharactersLong; i++)
    {
        NSRange range;
        range.location = characterIndexesLong[i];
        range.length = 1;
        [longString replaceCharactersInRange:range withString:@""];
    }

    for(int i = 0; i < commonCharactersShort; i++)
    {
        NSRange range;
        range.location = characterIndexesShort[i] - cut;
        range.length = 1;
        [shortString replaceCharactersInRange:range withString:@""];
        cut++;
    }