Question Definition
Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
Each number in C may only be used once in the combination. Note:
All numbers (including target) will be positive integers.
The solution set must not contain duplicate combinations.
For example, given candidate set [10, 1, 2, 7, 6, 1, 5] and target 8,
A solution set is:
[
[1, 7],
[1, 2, 5],
[2, 6],
[1, 1, 6]
]
Java Solution
class Solution {
public List<List<Integer>> combinationSum2(int[] candidates, int target) {
Arrays.sort(candidates);
List<List<Integer>> result = new LinkedList<>();
List<Integer> cur = new LinkedList<>();
dfs(candidates, target, 0, cur, result);
return result;
}
private void dfs(int[] candidates, int target, int start, List<Integer> cur, List<List<Integer>> result){
if(target < 0) return;
if(target == 0){
result.add(new LinkedList<>(cur));
return;
}
for(int i = start; i < candidates.length; i++){
if(i > start && candidates[i] == candidates[i - 1]) continue;
cur.add(candidates[i]);
dfs(candidates, target - candidates[i], i + 1, cur, result);
cur.remove(cur.size() - 1);
}
}
}
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