[LeetCode] 0040. Combination Sum II

Explore diverse LeetCode solutions in Python, C++, JavaScript, SQL, and TypeScript. Ideal for interview prep, learning, and code practice in multiple programming languages. Github Repo Link

內容目錄

Medium

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 <= 100
1 <= candidates[i] <= 50
1 <= target <= 30

Python

				
					# time complexity: O(2^n)
# space complexity: O(n)
from typing import List


class Solution:
    def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:
        answer = []
        candidates.sort()
        self.backtrack(candidates, target, 0, [], answer)
        return answer

    def backtrack(self, candidates, target: int, totalIdx: int, path: List[int], answer: List[int]):
        if target < 0:
            return
        if target == 0:
            answer.append(path)
            return
        for i in range(totalIdx, len(candidates)):
            if i > totalIdx and candidates[i] == candidates[i - 1]:
                continue
            self.backtrack(
                candidates,
                target - candidates[i],
                i + 1,
                path + [candidates[i]],
                answer,
            )


candidates = [10, 1, 2, 7, 6, 1, 5]
target = 8
print(Solution().combinationSum2(candidates, target))

Medium

Python

相關文章