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
主要問題輸入字符串有多種情況
不包含.的字符串
包含多個點的字符串
包含點的字符串後存在0的後綴，例如1.0.0與1的比較
對於字符串中.操作，在使用split切割字符串時要注意需要加“\\”
public class Solution {
public int compareVersion(String version1, String version2) {
String w1[]=version1.split("\\.");
String w2[]=version2.split("\\.");
int l1=w1.length;
int l2=w2.length;
int l=l1;
if(l2<l1)
l=l2;
int i=0;
for(i=0;i<l;i++)
{
int a=Integer.parseInt(w1[i]);
int b=Integer.parseInt(w2[i]);
if(a<b)
return -1;
if(a>b)
return 1;
}
if(l1<l2)
{
for(i=l;i<l2;i++)
if(Integer.parseInt(w2[i])>0)
return -1;
return 0;
}
else if(l1>l2)
{
for(i=l;i<l1;i++)
if(Integer.parseInt(w1[i])>0)
return 1;
return 0;
}
else
return 0;
}
}