Compare Version Numbers(STRING-TYPE CONVERTION)

QUESTION

Compare two version numbers version1 and version1.
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
1ST TRY

class Solution {
public:
    int compareVersion(string version1, string version2) {
        int integer1 = 0;
        int integer2 = 0;
        int i1 = 0;
        int i2 = 0;
        
        while(i1 < version1.length())
        {
            integer1 = 10*integer1 + version1[i1++] - '0';
            if(version1[i1] == '.') 
            {
                i1++;
                break;
            }
        }
        while(i2 < version2.length())
        {
            integer2 = 10*integer2 + version2[i2++] - '0';
            if(version2[i2] == '.') 
            {
                i2++;
                break;
            }
        }
        if(integer1 > integer2) return 1;
        else if(integer1 < integer2) return -1;
        
        integer1 = 0;
        integer2 = 0;
        while(i1 < version1.length())
        {
            integer1 = 10*integer1 + version1[i1++] - '0';
        }
        while(i2 < version2.length())
        {
            integer2 = 10*integer2 + version2[i2++] - '0';
        }
        if(integer1 > integer2) return 1;
        else if(integer1 < integer2) return -1;
        else return 0;
    }
};

Result: Wrong

Input: "1.1", "1.01.0"
Output: -1
Expected: 0

2ND TRY

考虑有不只一个小数点的情况

class Solution {
public:
    int compareVersion(string version1, string version2) {
        int integer1 = 0;
        int integer2 = 0;
        int i1 = 0;
        int i2 = 0;
        
        while(i1 < version1.length() || i2 < version2.length())
        {
            while(i1 < version1.length())
            {
                integer1 = 10*integer1 + version1[i1++] - '0';
                if(version1[i1] == '.') 
                {
                    i1++;
                    break;
                }
            }
            while(i2 < version2.length())
            {
                integer2 = 10*integer2 + version2[i2++] - '0';
                if(version2[i2] == '.') 
                {
                    i2++;
                    break;
                }
            }
            if(integer1 > integer2) return 1;
            else if(integer1 < integer2) return -1;
            
            integer1 = 0;
            integer2 = 0;
        }
        return 0;
    }
};

Result: Accepted