LeetCode Subsets solution details, leetcodesubsets

LeetCode Subsets solution details, leetcodesubsets

Returns all subsets of a given set containing different integers.

Note that the element arrangement in the subset must be non-descending, and the solution set must not contain duplicate subsets.

If S = [1, 2, 3], there is the following solution:

[  [3],  [1],  [2],  [1,2,3],  [1,3],  [2,3],  [1,2],  []]

// Class Solution {public List
 
  
> Subsets (int [] nums) {List
  
   
> Results = new ArrayList <> (); if (nums = null) {return results;} if (nums. length = 0) {results. add (new ArrayList
   
    
(); Return results;} Arrays. sort (nums); helper (new ArrayList
    
     
(), Nums, 0, results); return results;} private void helper (ArrayList
     
      
Subset, int [] nums, int startIndex, List
      
        > Results) {results. add (new ArrayList
       
         (Subset); for (int I = startIndex; I <nums. length; I ++) {subset. add (nums [I]); helper (subset, nums, I + 1, results); subset. remove (subset. size ()-1 );}}}
       
      
     
    
   
  
 

// Public class Solution {public List
 
  
> Subsets (int [] nums) {if (nums = null) {return null;} Arrays. sort (nums); List
  
   
> Result = new ArrayList <> (); Queue
   
    
> Que = new ArrayList <> (); que. offer (new ArrayList
    
     
(); While (! Que. isEmpty () {List
     
      
Subset = que. poll (); result. add (subset); for (int I = 0; I <nums. length; I ++) {if (subset. size () = 0 | subset. get (subset. size ()-1) <nums [I]) {List
      
        Temp = new ArrayList <> (subset); temp. add (nums [I]); que. offer (temp) ;}} return result ;}}