my easy python solution -

def quartiles(arr): sorted_arr = sorted(arr) n = len(sorted_arr)
mid = n // 2

if n % 2 == 0:
    low = sorted_arr[:mid]
    high = sorted_arr[mid:]
    q1 = int(median(low))
    q2 = int(median(sorted_arr))
    q3 = int(median(high))
else:
    low = sorted_arr[:mid]
    high = sorted_arr[mid+1:]
    q1 = int(median(low))
    q2 = int(median(sorted_arr))
    q3 = int(median(high))

return [q1, q2, q3]