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Thread: hi i need help with the outputs for number combinations, I want to restrict the outputs to suits of 3 numbers

  1. #1
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    Default hi i need help with the outputs for number combinations, I want to restrict the outputs to suits of 3 numbers

    Hi i need help to refine the code below, I want to be able to
    (A) Restrict the number of output values per line to 3 numbers,
    (B) Remove Duplicate lines, where the same numbers are duplicated just outputted in a different order.
    (C) Count the number of outlines
    (D) Add a fixed column to the outputs that has an ascending count from 1 upwards

    thanks a lot i'm very new to Coding and was able to come across this which aided in the concept of what i'm trying to achieve
    the code is as follows:

    package num.com.t1;
    import java.util.*;
    import java.util.concurrent.atomic.AtomicInteger;
    /**
    *
    *
    */
    public class NumComT1 {


    public static void main(String... args) {
    Bag<Integer> b = new Bag<>();
    b.countFor(1, 1);
    b.countFor(2, 1);
    b.countFor(3, 1);
    b.countFor(4, 1);
    b.countFor(5, 1);
    b.countFor(6, 1);
    b.countFor(7, 1);
    b.countFor(8, 1);

    Set<String> set = new LinkedHashSet<>();
    for (List<Integer> list : b.combinations()) {
    System.out.println(list);
    String s = list.toString();
    if (!set.add(s))
    System.err.println("Duplicate entry " + s);
    }
    }
    }

    class Bag<E> {
    final Map<E, AtomicInteger> countMap = new LinkedHashMap<>();

    void countFor(E e, int n) {
    countMap.put(e, new AtomicInteger(n));
    }

    void decrement(E e) {
    AtomicInteger ai = countMap.get(e);
    if (ai.decrementAndGet() < 1)
    countMap.remove(e);
    }

    void increment(E e) {
    AtomicInteger ai = countMap.get(e);
    if (ai == null)
    countMap.put(e, new AtomicInteger(1));
    else
    ai.incrementAndGet();
    }

    List<List<E>> combinations() {
    List<List<E>> ret = new ArrayList<>();
    List<E> current = new ArrayList<>();
    combinations0(ret, current);
    return ret;
    }

    private void combinations0(List<List<E>> ret, List<E> current) {
    if (countMap.isEmpty()) {
    ret.add(new ArrayList<E>(current));
    return;
    }
    int position = current.size();
    current.add(null);
    List<E> es = new ArrayList<>(countMap.keySet());
    if (es.get(0) instanceof Comparable)
    Collections.sort((List) es);
    for (E e : es) {
    current.set(position, e);
    decrement(e);
    combinations0(ret, current);
    increment(e);
    }
    current.remove(position);
    }
    }


  2. #2
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    Default Re: hi i need help with the outputs for number combinations, I want to restrict the outputs to suits of 3 numbers

    Welcome to the forum! Please read this topic to learn how to post code in code or highlight tags and other useful info for new members.

    Please post your code correctly using code or highlight tags which are explained near the top of the above link.

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