271. Encode and Decode Strings

Leetcode

Neetcode

Code

class Codec:
 
    def encode(self, strs):
        """Encodes a list of strings to a single string.
        
        :type strs: List[str]
        :rtype: str
        """
        res = ""
        for s in strs:
            res += str(len(s)) + "#" + s
        return res
 
    def decode(self, s):
        """Decodes a single string to a list of strings.
        
        :type s: str
        :rtype: List[str]
        """
        res = []
        i = 0
 
        while i < len(s):
            j = i
            while s[j] != "#":
                j += 1
            length = int(s[i:j])
            res.append(s[j+1: j+1+length])
            i = j+1+length
        return res