class Solution {public:    int compareVersion(string version1, string version2) {        vector<int> v1 = convert(version1);        vector<int> v2 = convert(version2);        int size = min(v1.size(), v2.size());        for (int i = 0; i < size; i++) {            if (v1[i] < v2[i]) {                return -1;            } else if (v1[i] > v2[i]) {                return 1;            }        }        if (v1.size() > size) return 1;        if (v2.size() > size) return -1;        return 0;    }        vector<int> convert(string &version) {        vector<int> result;        int len = version.size();        int num = 0;        for (int i = 0; i < len; i++) {            if (version[i] == ‘.‘) {                result.push_back(num);                num = 0;            } else {                num = num * 10 + (version[i] - ‘0‘);            }        }        result.push_back(num);        while (result.back() == 0) {            result.pop_back();        }        return result;    }};