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"""
Question
Medium
Design an algorithm to encode a list of strings to a single string.
The encoded string is then decoded back to the original list of strings.
Please implement encode and decode
Example 1:
Input: ["neet","code","love","you"]
Output:["neet","code","love","you"]
Example 2:
Input: ["we","say",":","yes"]
Output: ["we","say",":","yes"]
Constraints:
0 <= strs.length < 100
0 <= strs[i].length < 200
strs[i] contains only UTF-8 characters.
"""
from typing import Dict, List
class Solution:
"""
A class to solve string encode and decode from input list.
String encode and decode from the input strs: List[str] using a encode approach.
"""
def encode(self, strs: List[str]) -> str:
"""
string encode from the input strs: List[str] using a encode approach.
Args:
strs: List[str]: a list of strings
Returns:
str: a single string
"""
res: str = ""
for s in strs:
res += str(len(s)) + "#" + s
return res
def decode(self, s: str) -> List[str]:
"""
string decode from the input str: str using a encode approach.
Args:
s: str: a string
Returns:
res: List[str] a list of strings
"""
res: List = []
i: int = 0
while i < len(s):
j: int = i
while s[j] != "#":
j += 1
length: int = int(s[i:j])
i = j + 1
j = i + length
res.append(s[i:j])
i = j
return res
def print(self, examples: Dict) -> None:
"""
funciton to print the result.
Args:
example: Dict, a dictionary of examples
"""
for name, example in examples.items():
res_encode = self.encode(example)
print(f"{name}: {res_encode}")
res_decode = self.decode(res_encode)
print(f"{name}: {res_decode}")
def main(self):
"""
main function to call print function to test examples
"""
examples = {
"ex1": ["neet", "code", "love", "you"],
"ex2": ["we", "say", ":", "yes"],
"ex3": ["I", "love", "Yejin"],
}
# Passing the dictionary to the print method
self.print(examples)
solution = Solution()
solution.main()
"""
Solution
url: https://neetcode.io/problems/string-encode-and-decode
video: https://www.youtube.com/watch?v=B1k_sxOSgv8&embeds_referring_euri=https%3A%2F%2Fneetcode.io%2F&source_ve_path=Mjg2NjY
1. encode
time: O(n)
space: O(n)
code:
```python
class Solution:
def encode(self, strs: List[str]) -> str:
res = ""
for s in strs:
res += str(len(s)) + "#" + s
return res
def decode(self, s: str) -> List[str]:
res = []
i = 0
while i < len(s):
j = i
while s[j] != '#':
j += 1
length = int(s[i:j])
i = j + 1
j = i + length
res.append(s[i:j])
i = j
return res
```
"""
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