import math

#array = [10, 20, -3, 4, 50, 6]

array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
k=10
res = [[]]*k

def insertion_sort(res):

    print(res)


def scatter():
    minv = min(array)
    maxv = max(array)

    bucket_size= math.ceil((maxv-minv)/k) #roundup or your last elements won't have a bucket to go to
    for x in array:
        #print(x)
        bucket_place = math.ceil(x/bucket_size)-1
        #print("place for ", x, "is ", bucket_place, "\n")
        res[bucket_place].append(x)

def insert_sort_buckets():
    for x in res:#sort each sublist
        insertion_sort(x)

def bucket_sort():
    scatter()
    insert_sort_buckets()

bucket_sort()
print(res)