Implement quick sort.

[8igMac]

Requirement

• Implement quick sort that sort the a list of int from small to large.
• Create your own test (at least 3 test case, you know the reason. 😄 )
• Hint: Use the built-in type List<int>, but don't use List.sort 😅 .

function signiture

List<int> qsort(List<int> list) {
  // todo
  return list;
}

test example

void main() {
  test('Quick sort', () {
    expect(qsort([3, 2, 1]), [1, 2, 3]);
  });
}