(Leetcode) Combination Sum

Given a set of candidate numbers (C) and a target number (T), find all unique combinations in c< /c5> where the candidate numbers sums to T.

the&NBSP; same   Repeated number may be chosen From&NBSP; C  unlimited number of times.

Note:

• All numbers (including target) would be positive integers.
• Elements in a combination (a1, a 2, ..., ak) must is in non-descending order. (ie, a1 ≤ a2 ≤ ... ≤ ak).
• The solution set must not contain duplicate combinations.

For example, given candidate set2,3,6,7 and target 7 , &NBSP;
A solution set Is: [7] &NBSP;
[2, 2, 3] &NBSP;

Use the Backtracking method:

1 classSolution {2  Public:3     voidBackTrace (vector<int>& candidates,intSumintTarget, vector<vector<int> > &results,vector<int> &result,intindex)4     {5         if(Sum = =target)6         {7 results.push_back (result);8             return;9         }Ten         Else if(Sum >target) One         { A             return; -         } -         Else if(Sum <target) the         { -              for(inti = index; I < candidates.size (); + +i) -             { - Result.push_back (Candidates[i]); +BackTrace (candidates, sum +candidates[i],target,results,result,i); - Result.pop_back (); +             } A         } at          -     } -vector<vector<int>> Combinationsum (vector<int>& candidates,inttarget) { - sort (Candidates.begin (), Candidates.end ()); -vector<vector<int> >results; -vector<int>result; in         intindex =0; -         intsum =0; to          + BackTrace (candidates,sum,target,results,result,index); -  the         returnresults; *     } $};

(Leetcode) Combination Sum