Printing all subsets of a given array.

Question

I am trying to print all subsets of an array but getting IndexOutOfBoundException for the following code :-

public static void getSubsets(int in,int [] arr,List<Integer> store)
{
if(in==arr.length)
{
System.out.println(store);
return;
}
store.add(arr[in]);
getSubsets(in+1, arr, store);
store.remove(arr[in]);
getSubsets(in+1, arr, store);
}

function call => getSubsets(0, arr, new ArrayList<Integer>());

Answer 1

you are taking value from arr and it is used as index in
remove(arr[in])
result is unexpected (depends of values in arr)

arr = [1,2,3,4,5]

0 [] before add arr[0]
1 [1]
2 [1, 2]
3 [1, 2, 3]
4 [1, 2, 3, 4]
5 [1, 2, 3, 4, 5] if (5 == length)
[1, 2, 3, 4, 5] print result
return

now after first return
in == 4 and arr[4] == value5
you are use value from array as index !!
.remove( value5 ) //remove at index 5
actual possible index for store is 0-4 not 5 (length==5)

Exception IndexOutOfBoundsException:
Index: 5, Size: 5
at java.util.ArrayList.remove()

Answer 2

Is this C++ or Java or JavaScript? Tag only the language used in your question, tagging too much languages irrelevant to the question results in lesser answers

Answer 3

Rishi noted👍

Answer 4

Thank you so much zemiak