Update 0271-encode-and-decode-strings.py

Shortened the encode function to a one-liner.
Refactored decode function to cleanly use index variables i and j.

python/0271-encode-and-decode-strings.py

@@ -1,28 +1,19 @@
 class Solution:
- """
- @param: strs: a list of strings
- @return: encodes a list of strings to a single string.
- """
-
  def encode(self, strs):
- res = ""
- for s in strs:
- res += str(len(s)) + "#" + s
- return res
-
- """
- @param: s: A string
- @return: decodes a single string to a list of strings
- """
+ return ''.join(map(lambda s: str(len(s)) + '#' + s, strs))
 
  def decode(self, s):
- res, i = [], 0
-
+ res = []
+ i = 0
+
  while i < len(s):
  j = i
- while s[j] != "#":
+ while s[j] != '#':
  j += 1
  length = int(s[i:j])
- res.append(s[j + 1 : j + 1 + length])
- i = j + 1 + length
+ i = j + 1
+ j = i + length
+ res.append(s[i:j])
+ i = j
+
  return res