{ "data": { "question": { "questionId": "1433", "questionFrontendId": "2227", "boundTopicId": null, "title": "Encrypt and Decrypt Strings", "titleSlug": "encrypt-and-decrypt-strings", "content": "
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:
\n\nc
in the string, we find the index i
satisfying keys[i] == c
in keys
.c
with values[i]
in the string.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:
\n\ns
of length 2 occurring at an even index in the string, we find an i
such that values[i] == s
. If there are multiple valid i
, we choose any one of them. This means a string could have multiple possible strings it can decrypt to.s
with keys[i]
in the string.Implement the Encrypter
class:
Encrypter(char[] keys, String[] values, String[] dictionary)
Initializes the Encrypter
class with keys, values
, and dictionary
.String encrypt(String word1)
Encrypts word1
with the encryption process described above and returns the encrypted string.int decrypt(String word2)
Returns the number of possible strings word2
could decrypt to that also appear in dictionary
.\n
Example 1:
\n\n\nInput\n["Encrypter", "encrypt", "decrypt"]\n[[['a', 'b', 'c', 'd'], ["ei", "zf", "ei", "am"], ["abcd", "acbd", "adbc", "badc", "dacb", "cadb", "cbda", "abad"]], ["abcd"], ["eizfeiam"]]\nOutput\n[null, "eizfeiam", 2]\n\nExplanation\nEncrypter encrypter = new Encrypter([['a', 'b', 'c', 'd'], ["ei", "zf", "ei", "am"], ["abcd", "acbd", "adbc", "badc", "dacb", "cadb", "cbda", "abad"]);\nencrypter.encrypt("abcd"); // return "eizfeiam". \n // 'a' maps to "ei", 'b' maps to "zf", 'c' maps to "ei", and 'd' maps to "am".\nencrypter.decrypt("eizfeiam"); // return 2. \n // "ei" can map to 'a' or 'c', "zf" maps to 'b', and "am" maps to 'd'. \n // Thus, the possible strings after decryption are "abad", "cbad", "abcd", and "cbcd". \n // 2 of those strings, "abad" and "abcd", appear in dictionary, so the answer is 2.\n\n\n
\n
Constraints:
\n\n1 <= keys.length == values.length <= 26
values[i].length == 2
1 <= dictionary.length <= 100
1 <= dictionary[i].length <= 100
keys[i]
and dictionary[i]
are unique.1 <= word1.length <= 2000
1 <= word2.length <= 200
word1[i]
appear in keys
.word2.length
is even.keys
, values[i]
, dictionary[i]
, word1
, and word2
only contain lowercase English letters.200
calls will be made to encrypt
and decrypt
in total.Compiled with clang 11
using the latest C++ 17 standard.
Your code is compiled with level two optimization (-O2
). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
\"], \"java\": [\"Java\", \" OpenJDK 17
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Most standard library headers are already included automatically for your convenience.
\\r\\nIncludes Pair
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Python 2.7.12
.
Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
\\r\\n\\r\\nNote that Python 2.7 will not be maintained past 2020. For the latest Python, please choose Python3 instead.
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Your code is compiled with level one optimization (-O1
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Most standard library headers are already included automatically for your convenience.
\\r\\n\\r\\nFor hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:
\\r\\n\\r\\n1. Adding an item to a hash.\\r\\n
\\r\\nstruct hash_entry {\\r\\n int id; /* we'll use this field as the key */\\r\\n char name[10];\\r\\n UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n
2. Looking up an item in a hash:\\r\\n
\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n struct hash_entry *s;\\r\\n HASH_FIND_INT(users, &user_id, s);\\r\\n return s;\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n
3. Deleting an item in a hash:\\r\\n
\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n\\r\\n\"], \"csharp\": [\"C#\", \"\\r\\n\\r\\n
Your code is compiled with debug flag enabled (/debug
).
Node.js 16.13.2
.
Your code is run with --harmony
flag, enabling new ES6 features.
lodash.js library is included by default.
\\r\\n\\r\\nFor Priority Queue / Queue data structures, you may use datastructures-js/priority-queue and datastructures-js/queue.
\"], \"ruby\": [\"Ruby\", \"Ruby 3.1
Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms
\"], \"swift\": [\"Swift\", \"Swift 5.5.2
.
Go 1.17.6
.
Support https://godoc.org/github.com/emirpasic/gods library.
\"], \"python3\": [\"Python3\", \"Python 3.10
.
Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
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Kotlin 1.3.10
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Rust 1.58.1
Supports rand v0.6\\u00a0from crates.io
\"], \"php\": [\"PHP\", \"PHP 8.1
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With bcmath module
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Your code is run with --harmony
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lodash.js library is included by default.
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