小编Ale*_*ang的帖子

import java.util.ArrayList;

public class Subset { //Generate all subsets by generating all binary numbers
    public static ArrayList<ArrayList<Integer>> getSubsets2(ArrayList<Integer> set) {

        ArrayList<ArrayList<Integer>> allsubsets =
            new ArrayList<ArrayList<Integer>>();
        int max = 1 << set.size();             //there are 2 power n 
        for (int i = 0; i < max; i++) {
            ArrayList<Integer> subset = new ArrayList<Integer>();

            int index = 0;
            while (i > 0) {
                if ((i & 1) > 0) {
                    subset.add(set.get(index)); //Add elements to a new ArrayList
                }
                i >>= 1;
                index++;
            } …