Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Creative Commons License 

import java.util.ArrayList;

import java.util.List;

import java.util.Set;

public class Main {
    private static <T> void computeAllItemCombinationsRecursive(T[] input, Set<List<T>> output, List<T> combination,
            int pos, int maxLength) {
        if (pos == input.length && combination.size() == maxLength) {
            output.add(combination);
        }

        if (pos < input.length) {
            if (combination != null) {
                combination.add(input[pos]);
                if (combination.size() == maxLength) {
                    output.add(combination);
                } else {
                    for (int i = pos; i < input.length; ++i) {
                        computeAllItemCombinationsRecursive(input, output, combination, i + 1, maxLength);
                    }
                }
            }
            int lastPosToStartFrom = input.length - maxLength + 1;
            for (int i = pos; i < lastPosToStartFrom; ++i) {
                combination = new ArrayList<>(maxLength);
                combination.add(input[pos]);
                computeAllItemCombinationsRecursive(input, output, combination, i + 1, maxLength);
            }
        }
    }
}