2227. Encrypt and Decrypt Strings

Hard

50 Points

Array

Hash Table

String

Design

Trie

You are given a character array keys containing unique characters and a string array values containing strings of length 2. You are also given another string array dictionary that contains all permitted original strings after decryption. You should implement a data structure that can encrypt or decrypt a 0-indexed string. A string is encrypted with the following process: Note that in case a character of the string is not present in keys, the encryption process cannot be carried out, and an empty string "" is returned. A string is decrypted with the following process: Implement the Encrypter class:

Examples

Example 1

Input ["Encrypter", "encrypt", "decrypt"] [[['a', 'b', 'c', 'd'], ["ei", "zf", "ei", "am"], ["abcd", "acbd", "adbc", "badc", "dacb", "cadb", "cbda", "abad"]], ["abcd"], ["eizfeiam"]] Output [null, "eizfeiam", 2] Explanation Encrypter encrypter = new Encrypter([['a', 'b', 'c', 'd'], ["ei", "zf", "ei", "am"], ["abcd", "acbd", "adbc", "badc", "dacb", "cadb", "cbda", "abad"]); encrypter.encrypt("abcd"); // return "eizfeiam". // 'a' maps to "ei", 'b' maps to "zf", 'c' maps to "ei", and 'd' maps to "am". encrypter.decrypt("eizfeiam"); // return 2. // "ei" can map to 'a' or 'c', "zf" maps to 'b', and "am" maps to 'd'. // Thus, the possible strings after decryption are "abad", "cbad", "abcd", and "cbcd". // 2 of those strings, "abad" and "abcd", appear in dictionary, so the answer is 2.

Constraints

1 <= keys.length == values.length <= 26
values[i].length == 2
1 <= dictionary.length <= 100
1 <= dictionary[i].length <= 100
All keys[i] and dictionary[i] are unique.
1 <= word1.length <= 2000
2 <= word2.length <= 200
All word1[i] appear in keys.
word2.length is even.
keys, values[i], dictionary[i], word1, and word2 only contain lowercase English letters.
At most 200 calls will be made to encrypt and decrypt in total.