https://leetcode.com/problems/encode-and-decode-strings/
Encode and Decode Strings
Design an algorithm to encode a list of strings to a string. The encoded string is then sent over the network and is decoded back to the original list of strings.
Machine 1 (sender) has the function:
string encode(vector<string> strs) { // ... your code return encoded_string; }
Machine 2 (receiver) has the function:
vector<string> decode(string s) { //... your code return strs; }
So Machine 1 does:
string encoded_string = encode(strs);
and Machine 2 does:
vector<string> strs2 = decode(encoded_string);
strs2
in Machine 2 should be the same as strs
in Machine 1.
Implement the encode
and decode
methods.
Note:
- The string may contain any possible characters out of 256 valid ascii characters. Your algorithm should be generalized enough to work on any possible characters.
- Do not use class member/global/static variables to store states. Your encode and decode algorithms should be stateless.
- Do not rely on any library method such as
eval
or serialize methods. You should implement your own encode/decode algorithm.
Code:
class Codec: def encode(self, strs): return ''.join(s.replace('|', '||') + ' | ' for s in strs) def decode(self, s): return [t.replace('||', '|') for t in s.split(' | ')[:-1]]
Idea:
Use ” | ” as a delimiter of strings. If any string has “|” in it, you need to replace it with “||” in advance. When decoding, you first get ” | ” splitted words. Then, if there is any “||” in splitted words, you need to replace it back with “|”. Don’t forget to exclude the last element of `s.split(‘ | ‘)` since it is an empty string.
Reference: