{ "data": { "question": { "questionId": "2115", "questionFrontendId": "1987", "boundTopicId": null, "title": "Number of Unique Good Subsequences", "titleSlug": "number-of-unique-good-subsequences", "content": "
You are given a binary string binary
. A subsequence of binary
is considered good if it is not empty and has no leading zeros (with the exception of "0"
).
Find the number of unique good subsequences of binary
.
binary = "001"
, then all the good subsequences are ["0", "0", "1"]
, so the unique good subsequences are "0"
and "1"
. Note that subsequences "00"
, "01"
, and "001"
are not good because they have leading zeros.Return the number of unique good subsequences of binary
. Since the answer may be very large, return it modulo 109 + 7
.
A subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.
\n\n\n
Example 1:
\n\n\nInput: binary = "001"\nOutput: 2\nExplanation: The good subsequences of binary are ["0", "0", "1"].\nThe unique good subsequences are "0" and "1".\n\n\n
Example 2:
\n\n\nInput: binary = "11"\nOutput: 2\nExplanation: The good subsequences of binary are ["1", "1", "11"].\nThe unique good subsequences are "1" and "11".\n\n
Example 3:
\n\n\nInput: binary = "101"\nOutput: 5\nExplanation: The good subsequences of binary are ["1", "0", "1", "10", "11", "101"]. \nThe unique good subsequences are "0", "1", "10", "11", and "101".\n\n\n
\n
Constraints:
\n\n1 <= binary.length <= 105
binary
consists of only '0'
s and '1'
s.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.
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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
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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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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:
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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
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Node.js 16.13.2
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Your code is run with --harmony
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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
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Go 1.17.6
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Support https://godoc.org/github.com/emirpasic/gods library.
\"], \"python3\": [\"Python3\", \"Python 3.10
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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
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With bcmath module
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