Post

40 Combination Sum Ii

40 Combination Sum Ii

Combination Sum II image

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:

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**Input:** candidates = [10,1,2,7,6,1,5], target = 8
**Output:** 
[
[1,1,6],
[1,2,5],
[1,7],
[2,6]
]

Example 2:

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**Input:** candidates = [2,5,2,1,2], target = 5
**Output:** 
[
[1,2,2],
[5]
]

 

Constraints:

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1 <= candidates.length <= 100
1 <= candidates[i] <= 50
1 <= target <= 30
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class Solution:
    def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:
        visited = [0] * len(candidates)
        result = []
        candidates.sort()
        
        def Traverse(visited, start, target):
            if target < 0:
                return 
            if target == 0:
                res = [] 
                for k in range(len(visited)):
                    if visited[k] == 1:
                        res.append(candidates[k])
                result.append(res)
                return
            
            for k in range(start, len(candidates)):
                if k > start and candidates[k] == candidates[k - 1]:
                    continue
                if target - candidates[k] < 0:
                    break
                visited[k] = 1
                Traverse(visited, k + 1, target - candidates[k])
                visited[k] = 0

        Traverse(visited, 0, target)
        return result



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