LeetCode Entry

1784. Check if Binary String Has at Most One Segment of Ones

06.03.2026 easy 2026 kotlin rust

+0 pattern

1784. Check if Binary String Has at Most One Segment of Ones easy blog post substack youtube

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Problem TLDR

1+0* pattern #easy

Intuition

1. Regex ^1+0*$

Approach

• or just check of 01

Complexity

• Time complexity: \(O(n)\)

• Space complexity: \(O(1)\)

Code

// 7ms
    fun checkOnesSegment(s: String) =
    "01" !in s

// 0ms
    pub fn check_ones_segment(s: String) -> bool {
        !s.contains("01")
    }