[LeetCode] 165. Compare Version Numbers

轉自LeetCode

Compare two version numbers version1 and version2.
If version1 > version2 return 1, if version1 < version2 return -1, otherwise return 0.

You may assume that the version strings are non-empty and contain only digits and the . character.
The . character does not represent a decimal point and is used to separate number sequences.
For instance, 2.5 is not "two and a half" or "half way to version three", it is the fifth second-level revision of the second first-level revision.

Here is an example of version numbers ordering:

0.1 < 1.1 < 1.2 < 13.37

<Solution>
這題主要就是拆解 string 來做比較

首先注意測資有可能是 "1" 和 "1.0.0.1" 這種不等長的情況

想法如下

• 利用 stringstream 來做切分，每次都讀入一個整數和一個字元。所以在一開始初始化的時候，將原本的字串都多加一個 '.' 字元

• 不用整個字串都比完，只要有一個位元能比出大小，就回傳答案

code如下(參考資料)