def shellSort(input_list):
    
    gap = len(input_list) // 2
    while gap > 0:

        for i in range(gap, len(input_list)):
            temp = input_list[i]
            j = i
# Sort the sub list for this gap

            while j >= gap and input_list[j - gap] > temp:
                input_list[j] = input_list[j - gap]
                j = j-gap
            input_list[j] = temp

# Reduce the gap for the next element

        gap = gap//2

list = [19,2,31,45,30,11,121,27]

shellSort(list)
print(list)



#Time Complexity

#Worst Case Complexity: less than or equal to O(n2) Worst case complexity for shell sort is always less than or equal to O(n2) . ...

#Best Case Complexity: O(n*log n) ...

#Average Case Complexity: O(n*log n)#