ACSL #1 Submission (2019-2020) - Andrew Lau

package com.company;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;

public class Main {
    ArrayList<String> characters;
    String number;
    int position;
    int positionNumber;

    public Main(String N, int P){
        characters = new ArrayList<>();
        number = N;
        position = P;
        positionNumber = Integer.parseInt(number.substring(number.length() - P, number.length() - P + 1));
        for (int i = 0; i < number.length(); i++) {
            characters.add(number.substring(i, i + 1));
        }
        evaluate();
    }

    public void evaluate(){
        for (int i = 0; i < number.length() - position; i++){
            characters.set(i, String.valueOf(Integer.parseInt(characters.get(i)) + positionNumber));
        }
        characters.set((number.length() - position), numberOfPrimeFactors());
        for (int i = number.length() - position + 1; i < number.length(); i++){
            characters.set(i, String.valueOf(Math.abs(Integer.parseInt(characters.get(i)) - positionNumber)));
        }

        String finalResult = "";
        for (String s : characters){
            finalResult += s;
        }
        System.out.println(finalResult);
    }

    public String numberOfPrimeFactors(){
        Set<Integer> numFactors = new HashSet<>(); //To prevent repetitions of prime factors
        long longNumber = Long.parseLong(number);

        for (int i = 2; i <= longNumber; i++){ //Checks if it is a factor
            while (longNumber % i == 0){
                numFactors.add(i);
                longNumber /= i;
            }
        }

        return String.valueOf(numFactors.size());
    }

    public static void main(String[] args) {
        Main n1 = new Main("102438", 3);
        Main n2 = new Main("4329", 1);
        Main n3 = new Main("6710", 2);
        Main n4 = new Main("16807", 1);
        Main n5 = new Main("60098065452", 7);
    }
}