Get a string @ "ABSDFASDFSDFDSAFSD ..." in all permutations

Get a string @ "ABSDFASDFSDFDSAFSD ..." all permutations   length! /(same item)! * (same Item)! )-(int) numberofstring: (nsstring*) str   //nsstring *str [email protected] "adfsadfasdfasdfsadfsdaxfgghfgjtyy";    int sumlength = str.length;//The number of all characters    nsstring *mystr = @ "ABCDEFGHIJKLMNOPQRSTUVWXYZ";    Nsmutablearray *samecharnumberarr = [Nsmutablearray array];    for (int i=0; i<mystr.length; i++) {        NSString *charstr = [MyStr substringfromindex:i];        int number = [[str componentsseparatedbystring:charstr]count]-1;        if (number>1) {            [Samecharnumberarr addobject:[nsnumber numberwithint:number];        }    }    int textsum=1;    For (NSNumber *nub in Samecharnumberarr) {        textsum *= FAC ([nub intvalue]);    }       int numberofstr =  FAC (sumlength)/textsum;    NSLog (@ "The number of all permutations is%d", numberofstr);  return NUMBEROFSTR;} int FAC (int n) {    int rs=1;    while (n>1)        rs*=n--;    return RS;}

Get a string @ "ABSDFASDFSDFDSAFSD ..." in all permutations