Leetcode34: Compare Version Numbers

Compare two version numbers version1 and version2.

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

class Solution {
public:
int compareVersion(string version1, string version2) {
int lev1=0,lev2=0;
int id1=0,id2=0;
while(id1!=version1.length()||id2!=version2.length()){
lev1=0;
while(id1<version1.length()){
if(version1[id1]=='.'){
++id1;
break;
}
lev1=lev1*10+(version1[id1]-'0');
++id1;
}

lev2=0;
while(id2<version2.length()){
if(version2[id2]=='.'){
++id2;
break;
}
lev2=lev2*10+(version2[id2]-'0');
++id2;
}

if(lev1>lev2){
return 1;
}else if(lev1<lev2){
return -1;
}
}
return 0;
}
};