165. Compare Version Numbers | LeetCode | Swift

每日一題

https://leetcode.com/problems/compare-version-numbers/description/?envType=daily-question&envId=2025-09-19

日期

2025/9/19

步驟

1. 把字串分割後轉換成整數 (Int)
2. 走訪兩個整數陣列，如果有一個先走訪完了就補零
3. 兩個值不一樣的時候根據題目要求回傳 1 或 -1

程式碼

class Solution {
    func compareVersion(_ version1: String, _ version2: String) -> Int {
        let v1 = integers(version1)
        let v2 = integers(version2)
        let n = max(v1.count, v2.count)
        for index in 0..<n {
            let one = value(of: v1, at: index)
            let two = value(of: v2, at: index)
            if one != two {
                return one > two ? 1 : -1
            }
        }
        return 0
    }

    private func integers(_ string: String) -> [Int] {
        string.split(separator: ".").compactMap { Int($0) }
    }

    private func value(of numbers: [Int], at index: Int) -> Int {
        index < numbers.count ? numbers[index] : 0
    }
}