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1548. Check If All 1s Are At Least Length K Places Away

Array

Problem - Check If All 1s Are At Least Length K Places Away

Easy

Given an binary array nums and an integer k, return true if all 1's are at least k places away from each other, otherwise return false.

 

Example 1:

Input: nums = [1,0,0,0,1,0,0,1], k = 2
Output: true
Explanation: Each of the 1s are at least 2 places away from each other.

Example 2:

Input: nums = [1,0,0,1,0,1], k = 2
Output: false
Explanation: The second 1 and third 1 are only one apart from each other.

 

Constraints:

  • 1 <= nums.length <= 105
  • 0 <= k <= nums.length
  • nums[i] is 0 or 1

Solutions

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class Solution:
    def kLengthApart(self, nums: List[int], k: int) -> bool:
        # count = float('inf')
        # for num in nums:
        #     if num == 1:
        #         if count < k:
        #             return False
        #         count = 0
        #     else:
        #         count += 1
        # return True

        if k == 0:
            return True
        last = None
        for i, num in enumerate(nums):
            if num == 1:
                if last is not None and i - last <= k:
                    return False
                last = i
        return True

Submission Stats:

  • Runtime: 7 ms (80.42%)
  • Memory: 21.1 MB (65.80%)