What is the time complexity of LeetCode 1784. Check if Binary String Has at Most One Segment of Ones?

The Python solution on this page runs in O(n), where n is the length of the string s.

What is the space complexity of LeetCode 1784. Check if Binary String Has at Most One Segment of Ones?

The Python solution on this page uses O(1) auxiliary space.

Check if Binary String Has at Most One Segment of Ones — LeetCode 1784 Python Solution

EasyString

Problem: #1784
Pattern: Hash Map
Reading time: 2 min
Source: leetcode.com

The problem

Given a binary string s without leading zeros, return true if s contains at most one contiguous segment of ones. Otherwise, return false.

Example

Input: s = "1001"
Output: false
Explanation: The ones do not form a contiguous segment.

Python solution

Python

class Solution:
    def checkOnesSegment(self, s: str) -> bool:
        return '01' not in s

Complexity

Measure	Complexity
Time	O(n), where n is the length of the string s
Space	O(1) auxiliary

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 1784. Check if Binary String Has at Most One Segment of Ones is filed here because the reference solution below belongs to the algorithm family this hub collects, even though its LeetCode tags point elsewhere.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 1784. Check if Binary String Has at Most One Segment of Ones?: LeetCode 1784. Check if Binary String Has at Most One Segment of Ones is rated Easy on LeetCode.
What is the time complexity of LeetCode 1784. Check if Binary String Has at Most One Segment of Ones?: The Python solution on this page runs in O(n), where n is the length of the string s.
What is the space complexity of LeetCode 1784. Check if Binary String Has at Most One Segment of Ones?: The Python solution on this page uses O(1) auxiliary space.
What topics does LeetCode 1784. Check if Binary String Has at Most One Segment of Ones cover?: LeetCode 1784. Check if Binary String Has at Most One Segment of Ones is tagged String on LeetCode.