vector<int> splitVer(string s) {

int i = 0;

vector<int> res;

int ver = 0;

while (i < s.size()) {

char c = s[i];

if (c == '.') {

res.push_back(ver);

ver = 0;

} else {

ver = ver * 10 + (c - '0');

}

i++;

}

res.push_back(ver);

return res;

}

int compareVersion(string version1, string version2) {

vector<int> ver1s = splitVer(version1);

vector<int> ver2s = splitVer(version2);

int i = 0;

while (i < min(ver1s.size(), ver2s.size())) {

if (ver1s[i] > ver2s[i]) return 1;

if (ver1s[i] < ver2s[i]) return -1;

i++;

}

// special case "1.0" == "1"

for(; i < ver1s.size(); i++) if (ver1s[i] > 0) return 1;

for(; i < ver2s.size(); i++) if (ver2s[i] > 0) return -1;

return 0;

}