Given a set of distinct integers, nums, return all possible subsets (the power set).
Note: The solution set must not contain duplicate subsets.
Example:
Input: nums = [1,2,3] Output: [ [3], [1], [2], [1,2,3], [1,3], [2,3], [1,2], [] ]使用回溯法解决
import java.util.ArrayList; import java.util.Arrays; import java.util.List; class num78 { public List<List<Integer>> subsets(int[] nums) { List<List<Integer>> list = new ArrayList<>(); Arrays.sort(nums); backtrack(list, new ArrayList<>(), nums, 0); return list; } private void backtrack(List<List<Integer>> list , List<Integer> tempList, int [] nums, int start){ list.add(new ArrayList<>(tempList)); for(int i = start; i < nums.length; i++){ tempList.add(nums[i]); backtrack(list, tempList, nums, i + 1); tempList.remove(tempList.size() - 1); } } public static void main(String[] args) { int[] nums = {1, 2, 3}; num78 solution = new num78(); List<List<Integer>> result = solution.subsets(nums); for(List<Integer> list : result){ System.out.println(list); } } }
