Given a list of numbers that may has duplicate numbers, return all possible subsets
class Solution { /** * @param nums: A set of numbers. * @return: A list of lists. All valid subsets. */ public ArrayList<ArrayList<Integer>> subsetsWithDup(int[] nums) { ArrayList<ArrayList<Integer>> results = new ArrayList<ArrayList<Integer>>(); if (nums == null || nums.length == 0) { return results; } ArrayList<Integer> subset = new ArrayList<>(); Arrays.sort(nums); dfsHelp(nums, 0, subset, results); return results; } PRivate void dfsHelp(int[] nums, int index, ArrayList<Integer> subset, ArrayList<ArrayList<Integer>> results) { results.add(new ArrayList<Integer>(subset)); for (int i = index; i < nums.length; i++) { if (i != index && nums[i] == nums[i - 1]) { continue; } subset.add(nums[i]); dfsHelp(nums, i + 1, subset, results); subset.remove(subset.size() - 1); } } }新闻热点
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