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Java-Compare Version Numbers
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
Credits:
Special thanks to @ts for adding this problem and creating all test cases.
比较版本号的新旧
以 . 为界 依次比较每个 . 前的数大小 分出大小就输出 相等就继续 特殊情况是类似 1与1.0的 此时也认为他们相等 代码如下;
public class Solution { public static int compareVersion(String version1, String version2) { return compare(version1, 0, version2, 0); } public static int compare(String version1,int st1, String version2,int st2) { int ssa = 1; int ssb = 1; if (st1 == version1.length() || st1 == version1.length() + 1) { ssa = 0; if (st2 == version2.length() || st2 == version2.length() + 1) { return 0; } } if (st2 == version2.length() || st2 == version2.length() + 1) { ssb = 0; if (st1 == version1.length() || st1 == version1.length() + 1) { return 0; } } int i = st1; int a=0; if (ssa != 0) { String s1 = ""; for (; i < version1.length(); i++) { if (version1.charAt(i) == '.') break; else s1 = s1 + version1.charAt(i); } a = Integer.valueOf(s1); } int j = st2; int b=0; if (ssb != 0) { String s2 = ""; for (; j < version2.length(); j++) { if (version2.charAt(j) == '.') break; else s2 = s2 + version2.charAt(j); } b = Integer.valueOf(s2); } if (a > b) return 1; else { if (a < b) return -1; else { if(ssa==0||ssb==0)return 0; else return compare(version1, i + 1, version2, j + 1); } } }}
Java-Compare Version Numbers