165. Compare Version Numbers

class Solution {public:    int compareVersion(string version1, string version2) {        int i=0;        int j=0;        int n1=version1.size();        int n2=version2.size();        int num1=0;        int num2=0;        while(i<n1||j<n2)        {            while(i<n1&&version1[i]!='.')            {                num1=num1*10+(version1[i]-'0');                i++;            }            while(j<n2&&version2[j]!='.')            {                num2=num2*10+(version2[j]-'0');                j++;            }            if(num1>num2)                return 1;            else if(num1<num2)                return -1;            i++;            j++;            num1=0;            num2=0;        }        return 0;    }};