how recursion works in Java

Question

I am running a Java program in IntelliJ, it includes an recursion, and I have no idea how it works. Also I desire to see what the output of each step of recursion is. How can I check that with debugger.

Thank you guys, here is what I have.

 //Given a set of distinct integers, nums, return all possible subsets.
public List<List<Integer>> subsets(int[] num) {
    List<List<Integer>> result = new ArrayList<>();
    if(num == null || num.length == 0) {
        return result;
    }
    List<Integer> list = new ArrayList<Integer>();
    Arrays.sort(num);
    subsetsHelper(result, list, num, 0);

    return result;
}


private void subsetsHelper(List<List<Integer>> result,
                           List<Integer> list, int[] num, int pos) {

    result.add(new ArrayList<Integer>(list));

    for (int i = pos; i < num.length; i++) {

        list.add(num[i]);
        subsetsHelper(result, list, num, i + 1);
        list.remove(list.size() - 1);
    }
}

public static void main(String[] args){
    Subset_I test = new Subset_I();
    System.out.println(test.subsets(new int[] {0,1}));
}

Put a break point in the method that's recursive to see each step. — ChiefTwoPencils, Feb 15 '16 at 04:48
Possible duplicate of [understanding basic recursion](http://stackoverflow.com/questions/1949454/understanding-basic-recursion) — Dr.jacky, Feb 15 '16 at 04:53

score 0 · Answer 1 · answered Feb 15 '16 at 04:49

0

You can add a breakpoint in the code and then debug it.

The other alternative is to print out the values using System.out.println() and view the values in the console.

answered Feb 15 '16 at 04:49

Joyson

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how recursion works in Java

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