# 17.11.2025 [1437. Check If All 1's Are at Least Length K Places Away]

All ones k-distant #easy

17.11.2025

1437. Check If All 1’s Are at Least Length K Places Away easy blog post substack youtube

https://dmitrysamoylenko.com/2023/07/14/leetcode_daily.html

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Problem TLDR

All ones k-distant #easy

Intuition

Count zeros in-between.

Approach

• we can write it with 1 extra variable

Complexity

Time complexity: $$O(n)$$

Space complexity: $$O(1)$$

Code

// 3ms
    fun kLengthApart(nums: IntArray, k: Int): Boolean {
        var z = k
        return nums.all { n -> (n < 1 || z >= k).also { z = (1-n)*(z+1-n)}}
    }

// 0ms
    pub fn k_length_apart(n: Vec<i32>, k: i32) -> bool {
        let mut z = k;
        n.iter().all(|&n|{ let r = n < 1 || z >= k; z = (1-n)*(z+1-n); r})
    }