题解 | #比较版本号#

import java.util.*;


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
        int i = 0;
        int j = 0;
        while (i < version1.length() || j < version2.length()) {
            int num1 = 0;
            int num2 = 0;
            for (int k = i; k <= version1.length(); k++) {
                if (k == version1.length() || '.' == version1.charAt(k)) {
                    num1 = Integer.parseInt(version1.substring(i, k));
                    i = k + 1;
                    break;
                }
            }
            for (int k = j; k <= version2.length(); k++) {
                if (k == version2.length() || '.' == version2.charAt(k)) {
                    num2 = Integer.parseInt(version2.substring(j, k));
                    j = k + 1;
                    break;
                }
            }
            if (num1 < num2) {
                return -1;
            }
            if (num1 > num2) {
                return 1;
            }
        }
        return 0;
    }
}