535 Encode and Decode TinyURL 编码和解码精简URL地址

详见：https://leetcode.com/problems/encode-and-decode-tinyurl/description/

C++：

class Solution {
public:

    // Encodes a URL to a shortened URL.
    string encode(string longUrl)
    {
        url.push_back(longUrl);
        return "http://tinyurl.com/" + to_string(url.size() - 1);
    }

    // Decodes a shortened URL to its original URL.
    string decode(string shortUrl)
    {
        auto pos = shortUrl.find_last_of("/");
        return url[stoi(shortUrl.substr(pos + 1))];
    }

private:
    vector<string> url;
};

// Your Solution object will be instantiated and called as such:
// Solution solution;
// solution.decode(solution.encode(url));

参考：http://www.cnblogs.com/grandyang/p/6562209.html