# Python Program to remove elements that are less than K difference away in a list

• Last Updated : 11 Oct, 2020

Given a list, perform removal of those elements whose difference is less than K from its previous element.

Input : test_list = [3, 19, 5, 8, 10, 13], K = 4
Output : [3, 8, 13, 19]
Explanation : 5 – 3 = 2, 2<4, hence 5 is removed, similarly, 10 – 8 is 2, less than K.

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Input : test_list = [15, 7, 20], K = 4
Output : [7, 15, 20]
Explanation : No deletion required.

Approach: Using loop and sorted()

In this, first, the list has to be sorted and then removal of elements that do not have appropriate distance between its preceding and succeeding element is performed.

## Python3

 `# initializing list``test_list ``=` `[``3``, ``19``, ``4``, ``8``, ``10``, ``13``]`` ` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# initializing K ``K ``=` `4`` ` `# sorting list ``test_list ``=` `sorted``(test_list)`` ` `idx ``=` `0``while` `idx < ``len``(test_list) ``-` `1``:``     ` `    ``# checking for difference``    ``if` `test_list[idx] ``+` `K > test_list[idx ``+` `1``]:``         ` `        ``# deleting if K closer``        ``del` `test_list[idx ``+` `1``]``    ``else``:``        ``idx ``+``=` `1`` ` `# printing result ``print``(``"Required List : "` `+` `str``(test_list))`

Output:

The original list is : [3, 19, 4, 8, 10, 13]

Required List : [3, 8, 13, 19]

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