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Ruairí O'Brien
Ruairí O'Brien

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Day 25 - Check If All 1's Are at Least Length K Places Away

#leetcode #python #challenge

The Problem

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:

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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.
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Example 2:

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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.
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Example 3:

Input: nums = [1,1,1,1,1], k = 0 Output: true
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Example 4:

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

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

Tests 

import pytest from .Day25_CheckIfAll1sAreAtLeastLengthKPlacesAway import Solution s = Solution() @pytest.mark.parametrize( "nums,k,expected", [ ([1,0,0,0,1,0,0,1], 2, True), ([1,0,0,1,0,1], 2, False), ([1,1,1,1,1], 0, True), ([0,1,0,1], 1, True) ], ) def test_k_length_apart(nums, k, expected): assert s.kLengthApart(nums, k) == expected
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Solution 

from typing import List class Solution: def kLengthApart(self, nums: List[int], k: int) -> bool: current_dist = k for n in nums: if n == 1: if current_dist < k: return False current_dist = 0 else: current_dist += 1 return True
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Analysis

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Commentary

That one was easy. A little too easy....

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