乘风破浪：LeetCode真题_040_Combination Sum II

class Solution {
    List<List<Integer>> ans;
    public List<List<Integer>> combinationSum2(int[] candidates, int target) {
        Arrays.sort(candidates);
        ans = new ArrayList<>();
        track(candidates, 0, target, new ArrayList<>());
        return ans;
    }

    private void track(int[] candidates, int index, int target, List<Integer> list) {
        if (target == 0) {
            ans.add(list);
            return;
        }
        for (int i = index; i < candidates.length; i++) {
            if (target < candidates[i] || (i > index && candidates[i] == candidates[i - 1]))//重要
                 continue;
            List<Integer> temp = new ArrayList<>(list);
            temp.add(candidates[i]);
            track(candidates, i + 1, target - candidates[i], temp);
        }
    }
}