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题目来源
https://leetcode.com/problems/combination-sum/
Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
The same repeated number may be chosen from C unlimited number of times.
题意分析
Input: a list as candidates, a value named target
Output:the list number that sumed to target
Conditions:在list里面找若干个数，使得和为target，注意每个数可以取若干次
Note:
For example, given candidate set 2,3,6,7 and target 7,
A solution set is: [7] [2, 2, 3]
题目思路
先对list进行排序，然后穷举即可
AC代码（Python）
1 _author_ = "YE" 2 # -*- coding:utf-8 -*- 3 4 class Solution(object): 5 def find(self,candidates, target, start, valueList): 6 if target == 0: 7 Solution.ans.append(valueList) 8 length = len(candidates) 9 for i in range(start, length): 10 if candidates[i] > target: 11 return 12 self.find(candidates, target - candidates[i], i, valueList + [candidates[i]]) 13 14 def combinationSum(self, candidates, target): 15 """ 16 :type candidates: List[int] 17 :type target: int 18 :rtype: List[List[int]] 19 """ 20 candidates.sort() 21 Solution.ans = [] 22 self.find(candidates, target, 0, []) 23 return Solution.ans 24 25 s = Solution() 26 candidates = [2,3,6,7] 27 target = 7 28 print(s.combinationSum(candidates, target))
[LeetCode]题解（python）：039-Combination Sum
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原文地址：http://www.cnblogs.com/loadofleaf/p/5025742.html
