Question Definition
Given a set of distinct integers, nums, return all possible subsets (the power set).
**Note: **The solution set must not contain duplicate subsets.
For example,
If nums = [1,2,3], a solution is:
[
[3],
[1],
[2],
[1,2,3],
[1,3],
[2,3],
[1,2],
[]
]
Java Solution
class Solution {
public List<List<Integer>> subsets(int[] nums) {
Arrays.sort(nums);
List<List<Integer>> result = new LinkedList<>();
List<Integer> cur = new LinkedList<>();
result.add(new LinkedList<>());
for(int i = 1; i <= nums.length; i++){
dfs(nums, 0, i, cur, result);
}
return result;
}
private void dfs(int[] nums, int start, int length, List<Integer> cur, List<List<Integer>> result){
if(length == 0){
result.add(new LinkedList<>(cur));
}
for(int i = start; i < nums.length; i++){
if(i > start && nums[i] == nums[i - 1]) continue;
cur.add(nums[i]);
dfs(nums, i + 1, length - 1, cur, result);
cur.remove(cur.size() - 1);
}
}
}
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