Compare Version Numbers问题及解法

问题描述：

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

问题分析：

将version1和version2两个版本之间的对应数字分割好，不足的以0代替，然后依次对比大小即可。

过程详见代码：

class Solution {public:    int compareVersion(string version1, string version2) {        istringstream ss1(version1), ss2(version2);string v1, v2;while (!ss1.eof() || !ss2.eof()){int val1 = 0, val2 = 0;if (!ss1.eof()){getline(ss1, v1, '.');val1 = stoi(v1);}if (!ss2.eof()){getline(ss2, v2, '.');val2 = stoi(v2);}if (val1 > val2) return 1;if (val1 < val2) return -1;}return 0;    }};