Subsets (Power Set) in Java: Explanation & Practice

Generate all subsets of a set

Problem summary

Given an array of unique integers, return all possible subsets (the power set). Include the empty set and the set itself.

Starter code

public class Main {
    public static void main(String[] args) {
        int[] nums = {1, 2, 3};
        
        // Backtracking: for each element, include or exclude
        // Start with empty subset, add elements one by one
        // Print all subsets, one per line
    }
}

Expected output and test cases

[1,2,3] → 8 subsets

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

[0] → 2 subsets
```
[]
[0]
```
[] → just empty set
```
[]
```

Hints

At each index, decide: include or exclude current element
Backtracking: add element, recurse, remove element
Base case: when index reaches end, add current subset to result
Total subsets = 2^n

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