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Encode and Decode Strings

Detailed guide and Python implementation for the 'Encode and Decode Strings' problem.

Problem Statement

Easy

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.

Implement two functions:

- encode(strs: List[str]) -> str — Encodes a list of strings to a single string.

- decode(s: str) -> List[str] — Decodes a single string back to the original list of strings.

The encoded string should be able to handle any possible characters in the input strings, including special characters and empty strings.

Constraints
  • 0 <= len(strs) <= 200
  • 0 <= len(strs[i]) <= 200
  • strs[i] can contain any possible characters (0-255)

Examples

Example 1
Input
strs = ["hello", "world"]
Output
["hello", "world"]
Explanation

The list is encoded into a single string and then decoded back to the original list ["hello", "world"].

Example 2
Input
strs = [""]
Output
[""]
Explanation

A list containing a single empty string is encoded and decoded correctly.

Example 3
Input
strs = ["we", "say", ":", "yes"]
Output
["we", "say", ":", "yes"]
Explanation

Special characters like ":" are handled correctly during encoding and decoding.

Need a Hint?
Consider using Arrays & Hashing-specific data structures like sets or heaps.
Edge Cases to Watch
  • Empty input structures
  • Single element inputs
  • Large numerical bounds

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