【LeeCode】78. 子集

【题目描述】

给你一个整数数组 nums ，数组中的元素 互不相同 。返回该数组所有可能的子集（幂集）。

解集 不能 包含重复的子集。你可以按 任意顺序 返回解集。

https://leetcode.cn/problems/subsets/submissions/400275893/

【示例】

【代码】官网

import java.util.*;
/**
 * 2022-12-23
 */

class Solution {
    List<List<Integer>> res = new ArrayList<>();
    public List<List<Integer>> subsets(int[] nums){
        backtrace(nums, 0, new ArrayList<>());
        for (List<Integer> x : res){
            System.out.println(x);
        }
        return res;
    }

    private void backtrace(int[] nums, int index, List<Integer> list) {
        res.add(new ArrayList<>(list));
        for (int i = index; i < nums.length; i++) {
            list.add(nums[i]);
            backtrace(nums, i + 1, list);
            list.remove(list.size() - 1);
        }
    }
}

public class Test {
    public static void main(String[] args) {
        int[] nums =  {1, 2, 3};
        new Solution().subsets(nums);
    }
}

【代码】admin

package com.company;

import java.util.*;
// 2022-12-26

class Solution {
    List<List<Integer>> res = new LinkedList<>();
    LinkedList<Integer> list = new LinkedList<>();
    public List<List<Integer>> subsets(int[] nums){
        backtrace(nums, 0, list );
        for (List<Integer> re : res) {
            System.out.println(re);
        }

        return res;
    }

    private void backtrace(int[] nums, int index, LinkedList<Integer> list) {
        res.add(new LinkedList<>(list));
        for (int i = index; i < nums.length; i++) {
            list.add(nums[i]);
            backtrace(nums, i + 1, list);
            list.removeLast();
        }
    }
}
public class Test{
    public static void main(String[] args) {
        int[] arr = {1, 2, 3};
        new Solution().subsets(arr);
    }
}