Combination Sum II

標籤：

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]

 

 1 class Solution { 2 public: 3     vector<vector<int>> combinationSum2(vector<int>& candidates, int target) { 4         sort(candidates.begin(), candidates.end()); 5         vector<vector<int> > result; 6         vector<int> temp; 7          8         dfs(candidates, target, result, temp, 0); 9         return result;10     }11     12     void dfs(vector<int>& candidates, int diff, vector<vector<int> >& result, vector<int>& temp, int start){13         if(diff == 0){14             result.push_back(temp);15             return;16         }17         18         for(int i = start; i < candidates.size(); i++){19             if(diff < candidates[i]) return;20             21             //only add the first number into the vector if there are many22             if(i > start && candidates[i] == candidates[i - 1]) continue;23             24             temp.push_back(candidates[i]);25             dfs(candidates, diff - candidates[i], result, temp, i + 1);26             temp.pop_back();27         }28         29     }30 };

 

Combination Sum II