40. Combination Sum II

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

Each number in candidates 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.

Example 1:

Input: candidates = [10,1,2,7,6,1,5], target = 8,
A solution set is:
[
[1, 7],
[1, 2, 5],
[2, 6],
[1, 1, 6]
]

Example 2:

Input: candidates = [2,5,2,1,2], target = 5,
A solution set is:
[
[1,2,2],
[5]
]

class Solution:
    def combinationSum2(self, candidates, target):
        """
        :type candidates: List[int]
        :type target: int
        :rtype: List[List[int]]
        """
        res = set()
        candidates.sort()
        def dfs(pos,target,s):
            if pos>=len(candidates):
                return
            if candidates[pos]>target:
                return
            if candidates[pos]==target:
                res.add(tuple(s+[candidates[pos]]))
            dfs(pos+1,target-candidates[pos],s+[candidates[pos]])
            dfs(pos+1,target,s)
        dfs(0,target,[])
        return [list(i) for i in res]
原文地址:https://www.cnblogs.com/bernieloveslife/p/9792516.html