Cacher is the code snippet organizer for pro developers

/*
和39一模一样，除了24行和27行
i + 1不能算重复的
if(i > start && cadidates[i - 1] == candidates[i]) continue;
必须i > start
*/

class Solution {
    public List<List<Integer>> combinationSum2(int[] candidates, int target) {
        List<List<Integer>> res = new ArrayList<>();
        Arrays.sort(candidates);
        backtrack(res, new ArrayList<>(), candidates, target, 0);
        return res;
    }
    
    public void backtrack(List<List<Integer>> res, List<Integer> cur, int[] candidates, int target, int start) {
        if(target == 0) {
            res.add(new ArrayList<>(cur));
            return;
        } else if(target < 0) {
            return;
        } else {
            for(int i = start; i < candidates.length; i++) {
                if(i > start && candidates[i - 1] == candidates[i])
                    continue;
                cur.add(candidates[i]);
                backtrack(res, cur, candidates, target - candidates[i], i + 1);
                cur.remove(cur.size() - 1);
            }
        }
    }    
}