【leetcode刷题】20T21-组合总和

示例 1:
输入: candidates = [2,3,6,7], target = 7,
所求解集为:
[
  [7],
  [2,2,3]
]

示例 2:
输入: candidates = [2,3,5], target = 8,
所求解集为:
[
  [2,2,2,2],
  [2,3,3],
  [3,5]
]

class Solution(object):
    def combinationSum(self, candidates, target):
        """
        :type candidates: List[int]
        :type target: int
        :rtype: List[List[int]]
        """
        res = []
        candidates.sort()
        tmp = [[ci] for ci in candidates if ci <= target]
        while len(tmp) > 0:
            sum_t = sum(tmp[0])
            if sum_t == target:
                res.append(str(sorted(tmp.pop(0))))
                continue

            # 遍历元素，观察相加是否<=target
            for ci in candidates:
                if sum_t + ci <= target:
                    t = copy.copy(tmp[0])
                    t.append(ci)
                    tmp.append(t)
                else:
                    break
            tmp.pop(0)
        res = list(set(res))
        res = [eval(si) for si in res]
        return res