Compare two version numbers version1 and version1.
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
比较版本号大小,把'.'分开的部分分别比较,每部分string转为十进制,注意有"1.1.1.1"这种多个'.'的情况
Source
public int compareVersion(String version1, String version2) {
int i = 0, j = 0;
while(i < version1.length() || j < version2.length()){
int a = 0, b = 0;
while(i < version1.length() && version1.charAt(i) != '.'){ //判越界的要放在前面 否则放在后面容易报抛出异常 比如输入1,0时
a = a * 10 + (version1.charAt(i) - '0'); //注意减去'0'转换为数字
i++;
}
while(j < version2.length() && version2.charAt(j) != '.'){
b = b * 10 + (version2.charAt(j) - '0');
j++;
}
i++;
j++;
if(a > b) return 1;
if(a < b) return -1;
}
return 0;
}
Test
public static void main(String[] args){
String a = "01";
String b = "1";
System.out.println(new Solution().compareVersion(a, b));
}