How hard is LeetCode 165. Compare Version Numbers?

LeetCode 165. Compare Version Numbers is rated Medium on LeetCode.

What is the time complexity of LeetCode 165. Compare Version Numbers?

The Python solution on this page runs in O(\max(m, n)).

What is the space complexity of LeetCode 165. Compare Version Numbers?

The Python solution on this page uses O(1), where m and n are the lengths of the two strings auxiliary space.

What topics does LeetCode 165. Compare Version Numbers cover?

LeetCode 165. Compare Version Numbers is tagged Two Pointers and String on LeetCode.

Compare Version Numbers — LeetCode 165 Python Solution

MediumTwo PointersString

Problem: #165
Pattern: Two Pointers
Reading time: 3 min
Source: leetcode.com

The problem

Given two version strings, version1 and version2, compare them. A version string consists of revisions separated by dots '.'.

Python solution

Python

class Solution:
    def compareVersion(self, version1: str, version2: str) -> int:
        m, n = len(version1), len(version2)
        i = j = 0
        while i < m or j < n:
            a = b = 0
            while i < m and version1[i] != '.':
                a = a * 10 + int(version1[i])
                i += 1
            while j < n and version2[j] != '.':
                b = b * 10 + int(version2[j])
                j += 1
            if a != b:
                return -1 if a < b else 1
            i, j = i + 1, j + 1
        return 0

Complexity

Measure	Complexity
Time	O(\max(m, n))
Space	O(1), where m and n are the lengths of the two strings auxiliary

Pattern: Two Pointers

Use the order already in the input to discard half the search space at every step. LeetCode 165. Compare Version Numbers is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Two Pointers.

The two pointers guide has the Python template for the pattern and the 201 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 165. Compare Version Numbers?: LeetCode 165. Compare Version Numbers is rated Medium on LeetCode.
What is the time complexity of LeetCode 165. Compare Version Numbers?: The Python solution on this page runs in O(\max(m, n)).
What is the space complexity of LeetCode 165. Compare Version Numbers?: The Python solution on this page uses O(1), where m and n are the lengths of the two strings auxiliary space.
What topics does LeetCode 165. Compare Version Numbers cover?: LeetCode 165. Compare Version Numbers is tagged Two Pointers and String on LeetCode.