leetcode - Combination Sum II
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.
- Elements in a combination (a1, a2, … , ak) must be in non-descending order. (ie, a1 ≤ a2 ≤ … ≤ ak).
- 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]
class Solution { public: std::vector<std::vector<int> > combinationSum2(std::vector<int> &num, int target) { std::sort(num.begin(),num.end()); dfs(num,0,target); return res; } private: std::vector<int> path; std::vector<std::vector<int>> res; void dfs(std::vector<int> &num, int start, int target) { if(target == 0) { res.push_back(path); return; } else { for (int i = start; i < num.size(); i++) { if(i != start && num[i-1] == num[i]) { continue; } if(target >= num[i]) { path.push_back(num[i]); dfs(num,i+1,target-num[i]); path.pop_back(); } } } } };