{ "data": { "question": { "questionId": "2348", "questionFrontendId": "2266", "boundTopicId": null, "title": "Count Number of Texts", "titleSlug": "count-number-of-texts", "content": "
Alice is texting Bob using her phone. The mapping of digits to letters is shown in the figure below.
\n\nIn order to add a letter, Alice has to press the key of the corresponding digit i
times, where i
is the position of the letter in the key.
's'
, Alice has to press '7'
four times. Similarly, to add the letter 'k'
, Alice has to press '5'
twice.'0'
and '1'
do not map to any letters, so Alice does not use them.However, due to an error in transmission, Bob did not receive Alice's text message but received a string of pressed keys instead.
\n\n"bob"
, Bob received the string "2266622"
.Given a string pressedKeys
representing the string received by Bob, return the total number of possible text messages Alice could have sent.
Since the answer may be very large, return it modulo 109 + 7
.
\n
Example 1:
\n\n\nInput: pressedKeys = "22233"\nOutput: 8\nExplanation:\nThe possible text messages Alice could have sent are:\n"aaadd", "abdd", "badd", "cdd", "aaae", "abe", "bae", and "ce".\nSince there are 8 possible messages, we return 8.\n\n\n
Example 2:
\n\n\nInput: pressedKeys = "222222222222222222222222222222222222"\nOutput: 82876089\nExplanation:\nThere are 2082876103 possible text messages Alice could have sent.\nSince we need to return the answer modulo 109 + 7, we return 2082876103 % (109 + 7) = 82876089.\n\n\n
\n
Constraints:
\n\n1 <= pressedKeys.length <= 105
pressedKeys
only consists of digits from '2'
- '9'
.Compiled with clang 11
using the latest C++ 20 standard.
Your code is compiled with level two optimization (-O2
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Most standard library headers are already included automatically for your convenience.
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Node.js 16.13.2
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