Serialize and Deserialize Strings
Serialize and Deserialize a List of Strings. You are tasked with writing two functions: serialize and deserialize. The serialize function will take a list of strings as input and return a single string. The deserialize function will take this single string and reconstruct the original list of strings.
Details
- The
serializefunction should concatenate all strings in the list into a single string, with each original string's length encoded as a single character prefix. - The
deserializefunction should be able to take the single string and accurately split it back into the original list of strings, using the encoded length characters as guides.
For example, consider a list ["hello", "world"]. The serialization of this list might be "\x05hello\x05world", where \x05 indicates that the following string has a length of 5 characters.
Constraints
- The maximum length of any string is
65535(0xFFFF). - If a string's length exceeds the maximum, the
serializefunction should raise an exception. - The
deserializefunction should accurately handle any edge cases, such as empty strings or single-character strings. - Assume that all strings consist of ASCII characters only.
Examples
lst = ['hello', 'world'] serialized = serialize(lst) # serialized output: "\x05hello\x05world" deserialized = deserialize(serialized) # deserialized output should be: ['hello', 'world'] lst = [''] serialized = serialize(lst) # serialized output: "\x00" deserialized = deserialize(serialized) # deserialized output should be: [''] lst = ['a', 'bc', 'def'] serialized = serialize(lst) # serialized output: "\x01a\x02bc\x03def" deserialized = deserialize(serialized) # deserialized output should be: ['a', 'bc', 'def']
Our solution serializes and deserializes a list of strings by encoding the length of each string as a single character and concatenating it with the original string.
The serialize function processes the input list of strings by iterating through each string. For every string, it first encodes the length of the string as a single character using the encodeNumber function. The encoded length is then appended to a result list, followed by the string itself. The result list is ultimately joined into a single string, which represents the serialized form of the list of strings.
The deserialize function takes the serialized string and reconstructs the original list of strings. It starts by iterating through the serialized string, decoding the length of each string using the decodeNumber function, then extracting the string of that length from the serialized data. These strings are collected in a list and returned as the final deserialized result.
def encodeNumber(n):
if n > 0xFFFF:
raise "Number is too large to encode"
return chr(n)
def decodeNumber(s):
return ord(s)
def serialize(l):
ret = []
for word in l:
ret.append(encodeNumber(len(word)))
ret.append(word)
return ''.join(ret)
def deserialize(s):
ret = []
i = 0
if len(s) < 2:
return ret
while i < len(s):
wordLen = decodeNumber(s[i])
if wordLen + i > len(s):
raise "Bad encoding"
i += 1
word = s[i : i + wordLen]
ret.append(word)
i += wordLen
return retTime Complexity: The time complexity of both serialize and deserialize is O(n), where n is the total number of characters across all strings in the input list. In serialize, we iterate through every string, performing constant-time operations (encoding the length and appending the string) for each string. Similarly, in deserialize, we iterate through the serialized string, decoding lengths and extracting substrings, which are also constant-time operations for each step.
Space Complexity: The space complexity is O(n) for both functions since we store the serialized form of the input list (which has a size proportional to the total number of characters across all strings) and reconstruct the list in deserialize.
Daniel answers "Write a pair of functions to serialize and deserialize a list of strings."
Maybe we can use this solution: 1, connect all the strings together, and add an integer value ahead each string. 2, use Huffmans algorithm to encode the step 1 result, to make the result size smaller. 3, return the root of Huffmans tree.
This solution man be slower than the common serialize method, but it can save a lot of memory, I think, at lease doing serialize is mainly for tranfering data or storing data.