leetcode 165. Compare Version Numbers

165. 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

class Solution {
public:
    vector<int> chuli(string v)
    {
        vector<int> ret;
        int k=0;
        int all=0;
        while(k<v.size())
        {
            if(v[k]=='.')
            {    
                ret.push_back(all);
                all=0;
            } 
            else if(k==v.size()-1)
            { 
                all=all*10+int(v[k])-48;
                ret.push_back(all);
            }
            else
                all=all*10+int(v[k])-48;
            k++;      
        }
        return ret;
    }
    
    int compareVersion(string v1, string v2) 
    {
        if (v1 == v2)
            return 0;
         
        vector<int> vv1 = chuli(v1);
        vector<int> vv2 = chuli(v2);
         
        int length = min(vv1.size(), vv2.size());
        for(int i = 0; i < length; i++)
        {
            if(vv1[i] > vv2[i])
                return 1;
            else if(vv1[i] < vv2[i])    
                return -1;
        }
         
        if(length < vv1.size())        
        {
            for(int i = length; i < vv1.size(); i++)
            {
                if(vv1[i] != 0)
                    return 1;
            }        
        }
        else
        {
            for(int i = length; i < vv2.size(); i++)
            {
                if(vv2[i] != 0)
                    return -1;
            }
        }
        return 0;
    }
};