Compare Version Numbers

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

#include<iostream>#include<string>#include<vector>using namespace std;//转化为整数再比较int compareVersion(string version1, string version2) {int value1 = 0,value2 = 0;int index1=0,  index2 = 0;while (index1<version1.size()||index2<version2.size()){value1 =0;value2 =0;while (index1<version1.size()){if (version1[index1]=='.'){index1++;break;}value1 = 10*value1+version1[index1]-'0';index1++;}while (index2<version2.size()){if (version2[index2]=='.'){index2++;break;}value2 = 10*value2+version2[index2]-'0';index2++;}if (value1>value2)return 1;if (value2>value1)return -1;}return 0;}