Compare version numbers

Two Pointers String

46.1% acceptance

Jan 12, 2026

3161

2796

Given two version strings, version1 and version2, compare them. A version string consists of revisions separated by dots '.'. The value of the revision is its integer conversion ignoring leading zeros. To compare version strings, compare their revision values in left-to-right order. If one of the version strings has fewer revisions, treat the missing revision values as 0. Return the following: If version1 < version2, return -1. If version1 > version2, return 1. Otherwise, return 0.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn compare_version(version1: String, version2: String) -> i32 {
    let v1: Vec<i32> = version1.split('.').map(|s| s.parse().unwrap()).collect();
    let v2: Vec<i32> = version2.split('.').map(|s| s.parse().unwrap()).collect();
    
    let max_len = v1.len().max(v2.len());
    
    for i in 0..max_len {
      let num1 = if i < v1.len() { v1[i] } else { 0 };
      let num2 = if i < v2.len() { v2[i] } else { 0 };
      
      if num1 > num2 {
        return 1;
      } else if num1 < num2 {
        return -1;
      }
    }
    
    0
  }
}