Leetcode-Combinations Sum II

 1 public class Solution {
 2     public List<List<Integer>> combinationSum2(int[] num, int target) {
 3         int[] candidates = num;
 4         List<List<Integer>> resSet = new ArrayList<List<Integer>>();
 5         List<Integer> curRes = new ArrayList<Integer>();
 6         if (candidates.length==0) return resSet;
 7         Arrays.sort(candidates);
 8         int cur=0,end=candidates.length-1;
 9         for (int i=0;i<candidates.length;i++)
10             if (candidates[i]>target){
11                 end = i-1;
12                 break;         
13             }
14          
15 
16         sumRecur(candidates,cur,end,target,resSet,curRes);
17 
18         return resSet;
19         
20     }
21     
22     
23     public void sumRecur(int[] candidates, int cur, int end, int valLeft, List<List<Integer>> resSet, List<Integer> curRes){
24         if (valLeft==0){
25             List<Integer> temp = new ArrayList<Integer>();
26             temp.addAll(curRes);
27             resSet.add(temp);
28             return;
29         }
30 
31         if (cur>end) return;
32 
33         int newLeft = valLeft;
34         int curLen = curRes.size();
35         int nextIndex = cur;
36         while (nextIndex<=end && candidates[nextIndex]==candidates[cur]) nextIndex++;
37         
38         for (int i=cur;i<nextIndex;i++)
39             if (newLeft>=candidates[i]){
40                 curRes.add(candidates[i]);
41                 newLeft -= candidates[i];
42                 sumRecur(candidates,nextIndex,end,newLeft,resSet,curRes);
43             } else 
44                 break;
45 
46         while (curRes.size()!=curLen) curRes.remove(curRes.size()-1);
47 
48         sumRecur(candidates,nextIndex,end,valLeft,resSet,curRes);        
49     }
50 }