【LeetCode】C# 78、Subsets

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],

[]

]

给定一个集合，返回其所有子集合，包括空集。

思路：迭代，和上一题类似，不同的是这题把所有情况都录入result。

public class Solution {
public List<List<int>> Subsets(int[] nums) {
List<List<int>> list = new List<List<int>>();
Array.Sort(nums);
backtrack(list, new List<int>(), nums, 0);
return list;
}

private void backtrack(List<List<int>> list , List<int> tempList, int [] nums, int start){
list.Add(new List<int>(tempList));
for(int i = start; i < nums.Length; i++){
tempList.Add(nums[i]);
backtrack(list, tempList, nums, i + 1);
tempList.RemoveAt(tempList.Count - 1);
}
}
}