class Solution {
public:
int compareVersion(string version1, string version2) {
int i=0,j=0;
while(i<version1.size()||j<version2.size()){
long long x=0;
for(;i<version1.size()&&version1[i]!='.';i++){
x=x*10+version1[i]-'0';
}
++i;
long long y=0;
for(;j<version2.size()&&version2[j]!='.';j++){
y=y*10+version2[j]-'0';
}
++j;
if(x!=y){
return x>y?1:-1;
}
}
return 0;
}
};