Find All Lonely Numbers in the Array — LeetCode 2150 Python Solution

The problem

You are given an integer array nums. A number x is lonely when it appears only once, and no adjacent numbers (i.e.

Example

Input

nums = [10,6,5,8]

Output

[10,8]

Explanation

- 10 is a lonely number since it appears exactly once and 9 and 11 does not appear in nums.

Python solution

class Solution:
    def findLonely(self, nums: List[int]) -> List[int]:
        cnt = Counter(nums)
        return [
            x for x, v in cnt.items() if v == 1 and cnt[x - 1] == 0 and cnt[x + 1] == 0
        ]

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 2150. Find All Lonely Numbers in the Array is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Hash Table and Counting.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

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