# 39. Combination Sum

# Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), 
# find all unique combinations in candidates where the candidate numbers sums to target.
# The same repeated number may be chosen from candidates unlimited number of times.

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

# Example 1:
# Input: candidates = [2,3,6,7], target = 7,
# A solution set is:
# [
#   [7],
#   [2,2,3]
# ]

# Example 2:
# Input: candidates = [2,3,5], target = 8,
# A solution set is:
# [
#   [2,2,2,2],
#   [2,3,3],
#   [3,5]
# ]

class Solution:
	def combinationSum(self, candidates, target):
		"""
		:type candidates: List[int]
		:type target: int
		:rtype: List[List[int]]
		"""
		# candidates = list(set(candidates))
		candidates.sort()
		self.results = []
		self.dfs(candidates, target, 0, [])
		return self.results

	def dfs(self, candidates, target, idx, valueList):
		if target == 0:
			return self.results.append(valueList)
		
		for i in range(idx, len(candidates)):
			if target < candidates[i]:
				return
			
			self.dfs(candidates, target - candidates[i], i, valueList + [candidates[i]])