271_encode_decode_string.py

from typing import List

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

def run_tests():
    solution = Solution()
    test_cases = [
        [""],        # Single empty string
        [],         # Empty list
        ["we", "say", ":", "yes"],  # Multiple strings with special character
        ["neet", "code", "loves", "you"],  # Multiple normal strings
        ["#hello#world", "with#delimiter#"],  # Strings containing delimiter
    ]
    
    for test in test_cases:
        encoded = solution.encode(test)
        decoded = solution.decode(encoded)
        print(f"Original: {test}")
        print(f"Encoded: {encoded}")
        print(f"Decoded: {decoded}")
        print(f"Pass: {test == decoded}\n")

run_tests()