题解 | #比较版本号#

class Solution {
public:
    /**
     * 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
     */
    vector<string> split(string s, char op) {
        int n = s.size();
        vector<string> res;
        for(int i = 0; i < n; i++) {
            string ans = "";
            while(s[i] != op && i < n) {
                ans += s[i];
                i++;
            }
            res.push_back(ans);
        }
        return res;
    }
    int compare(string version1, string version2) {
        // write code here
        vector<string> s1 = split(version1, '.');
        vector<string> s2 = split(version2, '.');
        int l1 = s1.size();
        int l2 = s2.size();
        for(int i = 0; i < l1 && i < l2; i++) {
            long long num1 = 0;
            long long num2 = 0;
            for(int j = 0; j < s1[i].size(); j++) {
                num1 += num1 * 10 + s1[i][j] - '0';
            }
            for(int j = 0; j < s2[i].size(); j++) {
                num2 += num2 * 10 + s2[i][j] - '0';
            }
            if(num1 > num2)
                return 1;
            else if( num1 < num2)
                return -1;
        }
        if(l1 > l2) {
            for(int i = l2; i < l1; i++) {
                int num = 0;
                for(int j = 0; j < s1[i].size(); j ++)
                    num += num * 10 + s1[i][j] - '0';
                if( num > 0 )
                    return 1;
                else if(num < 0)
                    return -1;
            }
            return 0;
        }
            
        else if( l1 < l2) {
            for(int i = l1; i < l2; i++) {
                int num = 0;
                for(int j = 0; j < s2[i].size(); j ++)
                    num += num * 10 + s2[i][j] - '0';
                if( num > 0 )
                    return -1;
                else if(num < 0)
                    return 1;
            }
            return 0;
        }
        else
            return 0;
    }
};