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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Name of the class has to be "Main" only if the class is public. */
  8. class Ideone
  9. {
  10.     public List<List<Integer>> subsetsWithNew(int[] nums) {
  11.         List<List<Integer>> res = new ArrayList<>();
  12.         if(nums==null || nums.length==0) return res;
  13.         dfsWithNew(res, new ArrayList<>(), 0, nums);
  14.         return res;
  15.     }
  16.  
  17.     private void dfsWithNew(List<List<Integer>> res, List<Integer> list, int pos, int[] nums) {
  18.         res.add(new ArrayList<Integer>(list));
  19.         if(pos==nums.length+1) return;
  20.         for(int i=pos; i<nums.length; i++) {
  21.             list.add(nums[i]);
  22.             dfsWithNew(res, list, i+1, nums);
  23.             list.remove(list.size()-1);
  24.         }
  25.     }
  26.  
  27.     public List<List<Integer>> subsetsWithoutNew(int[] nums) {
  28.         List<List<Integer>> res = new ArrayList<>();
  29.         if(nums==null || nums.length==0) return res;
  30.         dfsWithoutNew(res, new ArrayList<>(), 0, nums);
  31.         return res;
  32.     }
  33.  
  34.     private void dfsWithoutNew(List<List<Integer>> res, List<Integer> list, int pos, int[] nums) {
  35.         res.add(list);
  36.         if(pos==nums.length+1) return;
  37.         for(int i=pos; i<nums.length; i++) {
  38.             list.add(nums[i]);
  39.             dfsWithoutNew(res, list, i+1, nums);
  40.             list.remove(list.size()-1);
  41.         }
  42.     }
  43.  
  44.     public static void main (String[] args) throws java.lang.Exception
  45.     {
  46.         Ideone app = new Ideone();
  47.         int[] nums = { 5, 2 };
  48.  
  49.         System.out.println("*** With new ***");
  50.         List<List<Integer>> subsets = app.subsetsWithNew(nums);
  51.         subsets.forEach(System.out::println);
  52.  
  53.         System.out.println("*** Without new ***");
  54.         subsets = app.subsetsWithoutNew(nums);
  55.         subsets.forEach(System.out::println);
  56.     }
  57. }
Success #stdin #stdout 0.16s 33268KB
comments (?)
stdin 
Standard input is empty
stdout 
*** With new ***
[]
[5]
[5, 2]
[2]
*** Without new ***
[]
[]
[]
[]
https://ideone.com/w2HTle
language:
Java (HotSpot 12)
created:
7 years ago
visibility:
public

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