文章作者：Tyan
博客：noahsnail.com | CSDN | 简书
1. 问题描述
Given a set of distinct integers, nums, return all possible subsets.
Note: The solution set must not contain duplicate subsets.
For example,
If nums = [1,2,3], a solution is:
[
[3],
[1],
[2],
[1,2,3],
[1,3],
[2,3],
[1,2],
[]
]
2. 求解
递归法
这道题类似于数组的组合问题，可以用递归法求解。N个数中每个数都分为要与不要两种情况，求解的过程如下图。递归的边界条件为N个数都遍历完了。当
递归过程
public class Solution {
public static List<List<Integer>> result = new ArrayList<List<Integer>>();
public List<List<Integer>> subsets(int[] nums) {
result.clear();
result.add(new ArrayList<Integer>());
combination(nums, 0, new ArrayList<Integer>());
return result;
}
public void combination(int[] nums, int index, List<Integer> list) {
if(index == nums.length) {
return;
}
combination(nums, index + 1, new ArrayList<Integer>(list));
list.add(nums[index]);
result.add(list);
combination(nums, index + 1, new ArrayList<Integer>(list));
}
}
