package com.lingyejun.dating.chap11.toutiao;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
/**
 * @Author: lingyejun
 * @Date: 2022/5/1
 * @Describe:
 * @Modified By:
 */
public class CompareVersionNumbers {
    public static int compareVersions(String version1, String version2) {
        String[] levels1 = version1.split("\\.");
        String[] levels2 = version2.split("\\.");
        int length = Math.max(levels1.length, levels2.length);
        for (int i = 0; i < length; i++) {
            Integer v1 = i < levels1.length ? Integer.parseInt(levels1[i]) : 0;
            Integer v2 = i < levels2.length ? Integer.parseInt(levels2[i]) : 0;
            // 对每一段的版本号从高位到低位进行判断
            int compare = v1.compareTo(v2);
            // 如果当前段版本号相同，则继续比较下一段，若当前段能判断出版本高低则直接返回
            if (compare != 0) {
                return compare;
            }
        }
        return 0;
    }
    public static void main(String[] args) {
        String version1 = "1.23.789";
        String version2 = "1.33.6678";
        int compare = compareVersions(version1, version2);
        System.out.println(compare);
        String version3 = "11.1.2";
        List<String> versionList = Arrays.asList(version1, version3, version2);
        List<String> sortedVersionList = versionList.stream()
                .sorted(CompareVersionNumbers::compareVersions)
                .sorted(Comparator.reverseOrder())
                .collect(Collectors.toList());
        System.out.println(sortedVersionList);
        String maxVersion = versionList.stream()
                .sorted(CompareVersionNumbers::compareVersions)
                .sorted(Comparator.reverseOrder())
                .findFirst().orElse(null);
        System.out.println(maxVersion);
    }
}