Strong Password Hackerrank

 static int minimumNumber(int n, String password) {
        // Return the minimum number of characters to make the password strong
        char[] pw = password.toCharArray();
        int specialCharacters =0;
        int numbers =0;
        int lowerCase =0;
        int upperCase =0;
        String special_characters = "!@#$%^&*()-+";
        for(int i=0;i<n;i++){
            if((int)pw[i]>=48 && (int)pw[i]<=57)
                numbers++;
            else if((int)pw[i]>=65 && (int)pw[i]<=90)
                upperCase++;
            else if((int)pw[i]>=97 && (int)pw[i]<=122)
                lowerCase++;
            else if(special_characters.contains(""+pw[i]))
                specialCharacters++;
            if(numbers>=1 && upperCase >=1 && lowerCase>=1 && pw.length>=6 && specialCharacters>=1){
                return 0;
            }
        }
        if(n >=6){
            int count =0;
            if(numbers==0)
                count++;
            if(upperCase==0)
                count++;
            if(lowerCase==0)
                count++;
            if(specialCharacters==0)
                count++;
            return count;
        }else{
            int count =0;
            if(numbers==0)
                count++;
            if(upperCase==0)
                count++;
            if(lowerCase==0)
                count++;
            if(specialCharacters==0)
                count++;
            int ans = count+n;
            if(ans>=6)
                return count;
            return 6-pw.length;
        }
    }