40. Combination Sum II
Đề Bài
Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target.
Each number in candidates may only be used once in the combination.
Note: The solution set must not contain duplicate combinations.
Example 1:
Input: candidates = [10,1,2,7,6,1,5], target = 8 Output: [ [1,1,6], [1,2,5], [1,7], [2,6] ]
Example 2:
Input: candidates = [2,5,2,1,2], target = 5 Output: [ [1,2,2], [5] ]
Constraints:
1 <= candidates.length <= 1001 <= candidates[i] <= 501 <= target <= 30
Thuật Toán & Kỹ Thuật
⏱️ Thời gian
O(n log n)
💾 Không gian
O(n)
Lời Giải
Python
0040-combination-sum-ii.py
class Solution:
def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:
candidates.sort()
n = len(candidates)
ans = set()
sumCandi = sum(candidates)
def dfs(i, s, path):
if s == target:
ans.add(tuple(path))
return
if i == n or s > target:
return
for j in range(i, n):
if j > i and candidates[j - 1] == candidates[j]:
continue
dfs(j + 1, s + candidates[j], path + [candidates[j]])
dfs(0, 0, [])
return ans