## leetcode 216. Combination Sum III Add to List (枚举子集，限定集合大小，和为定值）

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers.

## leetcode 77. Combinations (枚举子集，限定集合大小)

Given two integers n and k, return all possible combinations of k numbers out of 1 … n.

## leetcode 40. Combination Sum II (枚举子集，和为定值)

• Total Accepted: 106670
• Total Submissions: 329718
• Difficulty: Medium
• Contributor: LeetCode

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.

Each number in C may only be used once in the combination.

Note:

• All numbers (including target) will be positive integers.
• The solution set must not contain duplicate combinations.

## 90. Subsets II (枚举子集)

Given a collection of integers that might contain duplicates, nums, return all possible subsets.

Note: The solution set must not contain duplicate subsets.

For example,
If nums = [1,2,2], a solution is:

（还有种更飘逸的…先不写了orz