【leetcode】1437. Check If All 1's Are at Least Length K Places Away

题目如下：

Given an array nums of 0s and 1s 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.

Example 3:

Input: nums = [1,1,1,1,1], k = 0
Output: true

Example 4:

Input: nums = [0,1,0,1], k = 1
Output: true

Constraints:

• 1 <= nums.length <= 10^5
• 0 <= k <= nums.length
• nums[i] is 0 or 1

解题思路：感觉本题难度应该是Easy而不是Medium。

代码如下：

class Solution(object):
    def kLengthApart(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: bool
        """
        last_one = None
        for i in range(len(nums)):
            if nums[i] == 1 and last_one == None:
                last_one = i
            elif nums[i] == 1 and last_one != None:
                if i - last_one - 1 < k:
                    return False
                last_one = i
        return True