需要考虑版本号比较长的情况



public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
     *
     * 比较版本号
     * @param version1 string字符串 
     * @param version2 string字符串 
     * @return int整型
     */
    public int compare (String version1, String version2) {
        // write code here
        String[] str1 = version1.split("\\.");
        String[] str2 = version2.split("\\.");
        int len = Math.max(str1.length, str2.length);
        for (int i = 0; i < len; i++) {
            String a = i < str1.length ? str1[i] : "0";
            String b = i < str2.length ? str2[i] : "0";
            for (int j = 0; j < a.length(); j++) {
                if (j == a.length() - 1 || a.charAt(j) != '0') {
                    a = a.substring(j);
                    break;
                }
            }
            for (int j = 0; j < b.length(); j++) {
                if (j == b.length() - 1 || b.charAt(j) != '0') {
                    b = b.substring(j);
                    break;
                }
            }
            if (a.length() > b.length()) {
                return 1;
            } else if (a.length() < b.length()) {
                return -1;
            } else {
                if (a.compareTo(b) > 0) {
                    return 1;
                } else if (a.compareTo(b) < 0) {
                    return -1;
                }
            }
        }
        return 0;
    }
}