Python program to find Non-K distant elements

When it is required to find non 'K' distant elements, a simple iteration along with the 'append' method is used. Non-K distant elements are those numbers in a list that do not have any other number at exactly K distance from them.

What are Non-K Distant Elements?

An element is considered non-K distant if neither (element + K) nor (element - K) exists in the same list. For example, with K=2, the number 91 is non-K distant if neither 89 nor 93 exists in the list.

Example

Below is a demonstration of finding non-K distant elements ?

my_list = [91, 13, 19, 25, 35, 3, 9, 11, 0]

print("The list is :")
print(my_list)

my_key = 2
print("The key is")
print(my_key)

my_result = []

for element in my_list:
    if element + my_key not in my_list and element - my_key not in my_list:
        my_result.append(element)

print("The resultant list is :")
print(my_result)

Output

The list is :
[91, 13, 19, 25, 35, 3, 9, 11, 0]
The key is
2
The resultant list is :
[91, 19, 25, 35, 3, 0]

How It Works

Let's trace through the logic with K=2 :

• 91: Neither 89 nor 93 exists in the list ? Non-K distant

• 13: 11 exists in the list (13-2=11) ? K distant

• 19: Neither 17 nor 21 exists in the list ? Non-K distant

• 9: 11 exists in the list (9+2=11) ? K distant

Alternative Implementation Using List Comprehension

The same logic can be implemented more concisely using list comprehension :

my_list = [91, 13, 19, 25, 35, 3, 9, 11, 0]
my_key = 2

my_result = [element for element in my_list 
             if element + my_key not in my_list and element - my_key not in my_list]

print("Non-K distant elements:", my_result)

Non-K distant elements: [91, 19, 25, 35, 3, 0]

Conclusion

Non-K distant elements are identified by checking if neither (element + K) nor (element - K) exists in the list. This algorithm has O(n²) time complexity due to the 'in' operator being called for each element.