40. Combination Sum II

去重判断。。。。

public List<List<Integer>> combinationSum2(int[] candidates, int target) {
    List<List<Integer>> res = new ArrayList<>();
    List<Integer> path = new ArrayList<>();
    Arrays.sort(candidates);
    dfs(candidates, path, res, target, 0);
    return res;
}

public void dfs(int[] candidates, List<Integer> path, List<List<Integer>> res, int target, int pointer) {
    if (target < 0) return;
    else if (target == 0) res.add(new ArrayList<>(path));
    else {
        for (int i = pointer; i < candidates.length; i++) {
            if (i > pointer && candidates[i] == candidates[i - 1]) continue;
            path.add(candidates[i]);
            dfs(candidates, path, res, target - candidates[i], i + 1);
            path.remove(path.size() - 1);
        }
    }
}