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.
Input: candidates = [2,3,6,7], target = 7,
A solution set is:
[
[7],
[2,2,3]
]Input: candidates = [2,3,5], target = 8,
A solution set is:
[
[2,2,2,2],
[2,3,3],
[3,5]
]参考 46. Permutations 认真学习一下回溯思想。
思考题：如何做剪枝？这道题通过做剪枝从 164ms 优化到了 9ms。
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] ]
link:{sourcedir}/_0039_CombinationSum.java[role=include]