Given a range, the task here is to write a python program that can update the list elements falling under a given index range with a specified number.
Input : test_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1], i, j = 4, 8, K = 9
Output : [4, 6, 8, 1, 9, 9, 9, 9, 12, 3, 9, 1]
Explanation : List is updated with 9 from 4th to 8th index.
Input : test_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1], i, j = 4, 8, K = 8
Output : [4, 6, 8, 1, 8, 8, 8, 8, 12, 3, 9, 1]
Explanation : List is updated with 8 from 4th to 8th index.
Method 1 : Using slicing and * operator
In this, we perform task of getting elements of range using slicing and * operator is used to perform update and provide required elements to fill updates.
Program:
Python3
# initializing listtest_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1]# printing original listprint("The original list is : " + str(test_list))# initializing i, ji, j = 4, 8# initializing KK = 9# getting range using slicing and# required elements using * operatortest_list[i:j] = [K] * (j - i)# printing resultprint("Range Updated list : " + str(test_list)) |
Output:
The original list is : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1]
Range Updated list : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1, 9]
Time Complexity: O(n)
Auxiliary Space: O(1)
Method 2 : Using repeat() and list slicing
The similar task can also be performed using repeat(), which uses unbuilt constructs to get required elements.
Program:
Python3
from itertools import repeat# initializing listtest_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1]# printing original listprint("The original list is : " + str(test_list))# initializing i, ji, j = 4, 8# initializing KK = 9# getting range using slicing and# required elements using repeat()test_list[i:j] = repeat(K, (j - i))# printing resultprint("Range Updated list : " + str(test_list)) |
Output:
The original list is : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1]
Range Updated list : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1, 9]
Time Complexity: O(n) where n is the number of elements in the list “test_list”. The repeat() and list slicing is used to perform the task and it takes O(n) time.
Auxiliary Space: O(1) additional space not required
