Java Calculate Sequence with Queue

Question

I have the following sequence of numbers:

S1 = N, S2 = S1 + 1, S3 = 2*S1 + 1, S4 = S1 + 2, S5 = S2 + 1, S6 = 2*S2 + 1, S7 = S2 + 2 ... 

Using the ArrayDeque<E> class, I have to write a program to print its first 50 members for given N. Examples:

input 2
output 2 3 5 4 4 7 5 6 11 7 5 9 6 ...

This is my code. The problem is that I can't update next S

import java.util.ArrayDeque;
import java.util.Queue;
import java.util.Scanner;

public class p04 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int numN = scanner.nextInt();
        scanner.close();
        int counter = 1;
        int nexS = numN;
        Queue<Integer> fifty = new ArrayDeque<>();
        for (int i = 0; i < 50; i++) {
            if (i == 0){
                fifty.add(numN);
            }else {
                if (counter == 1){
                    counter++;
                    numN = nexS + 1;
                    fifty.add(numN);
                }else if (counter == 2){
                    counter++;
                    numN = (nexS * 2) + 1;
                    fifty.add(numN);
                }else {
                    counter = 1;
                    numN = nexS +2;
                    fifty.add(numN);
                    nexS = nexS + 1;
                }
            }
        }

        for (Integer integer : fifty) {
            System.out.print(integer + " ");
        }
    }
}

Answer 1

The way you solve this problem it's easier to solve It with ArrayList. I think that my solution is more queue oriented and that was your task. So this is my take:

import java.util.ArrayDeque;
import java.util.Scanner;

public class SequenceQuestion {

    public static void constructSequence(int start, int seqLength) {
        ArrayDeque<Integer> queue = new ArrayDeque<>();
        queue.add(start);
        System.out.print(start);
        for (int i = 0; i < seqLength - 1; i++) {
            int print = 0;
            if (i % 3 == 0 && i != 0) queue.remove();

            if (i % 3 == 0) {
                print = queue.peek() + 1;
                queue.add(print);
            } else if (i % 3 == 1) {
                print = queue.peek() * 2 + 1;
                queue.add(print);
            } else if (i % 3 == 2) {
                print = queue.peek() + 2;
                queue.add(print);
            }
            System.out.print(", " + print);
        }
    }

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        constructSequence(s.nextInt(), 50);
    }
}

You don't need counters because you already have one (i) and if you always check for mod 3 at the beginning and if equals to 0, remove the first element from queue. I see that this is the place you had trouble with.