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How to Solve Count Number of Texts Problem
Master the Count Number of Texts LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
Phantom Code generates complete solutions and debugging hints that you can use while explaining your approach, so you stay calm and in control.
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Start Free for WindowsMedium#2266
LeetCode ProblemCount Number of Texts
Alice is texting Bob using her phone. The mapping of digits to letters is shown in the figure below. In 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. However, due to an error in transmission, Bob did not receive Alice's text message but received a string of pressed keys instead. 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.
Hash TableMathStringDynamic Programming
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Problem Breakdown
Understanding the Count Number of Texts Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
Alice is texting Bob using her phone. The mapping of digits to letters is shown in the figure below. In 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. However, due to an error in transmission, Bob did not receive Alice's text message but received a string of pressed keys instead. 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.
MediumProblem #2266
LeetCodeCount Number of Texts
Related Topics
Hash TableMathStringDynamic Programming
How Phantom Code Helps
Get real-time assistance for Count Number of Texts problems during coding interviews. Phantom Code provides instant solutions and explanations.
Examples
# Example 1
Input
pressedKeys = "22233"
Output
8
# Example 2
Input
pressedKeys = "222222222222222222222222222222222222"
Output
82876089
Constraints
1 <= pressedKeys.length <= 105
pressedKeys only consists of digits from '2' - '9'.
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Solve Count Number of Texts — Alice is texting Bob using her phone. The mapping of digits to letters is shown ...
Here's the optimal approach using Hash Table:
def solve(input):
# Optimal O(n) solution
return result
Time: O(n) | Space: O(n)
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Undetectability Checklist
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Platform Compatibility
Zoom
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Google Meet
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HackerRank
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CodeSignal
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CoderPad
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Teams
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Undetectability and technical details
Our native desktop architecture avoids common detection vectors used by browser extensions. We provide a clear checklist so you can run basic checks and confirm the app will be invisible.
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We work with Zoom, HackerRank, CodeSignal, CoderPad and other web-based platforms. Check the compatibility note and request a browser link if a specific desktop app is unsupported.
Frequently Asked Questions
Common questions about solving Count Number of Texts and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Count Number of Texts during interviews?
Phantom Code generates complete solutions instantly with proper complexity analysis, letting you focus on explaining your approach and demonstrating problem-solving skills rather than getting stuck on implementation details during high-pressure situations.
What if the interviewer asks follow-up questions or modifications to problems like Count Number of Texts?
Phantom Code adapts in real-time. Screenshot the modified problem or use audio mode to capture the interviewer's follow-up, and get an updated solution within seconds — including edge cases and optimizations.
Can Phantom Code help me communicate my solution for problems like Count Number of Texts?
Yes. Phantom Code provides step-by-step approach explanations with 3 progressive thoughts, so you can walk through your solution naturally. It also provides time and space complexity analysis to discuss trade-offs.
How does Phantom Code assist with different programming languages for Count Number of Texts type problems?
Phantom Code supports 11 programming languages including Python, Java, C++, JavaScript, TypeScript, Go, Rust, Ruby, Swift, Kotlin, and C#. Set your preferred language and get idiomatic solutions.
What coding mistakes does Phantom Code help me avoid during Count Number of Texts interviews?
Phantom Code catches common mistakes like off-by-one errors, missing edge cases, incorrect base conditions, and suboptimal approaches. It provides clean, well-structured code that handles all edge cases.
Is Phantom Code detectable when solving problems like Count Number of Texts during live interviews?
No. Phantom Code runs as an invisible desktop overlay that doesn't appear in screen shares, recordings, or proctoring software. It works with Zoom, HackerRank, CodeSignal, CoderPad, and all major platforms.
How does Phantom Code help when I'm struggling with Count Number of Texts style questions under pressure?
The AI provides structured guidance: first the approach (what algorithm/data structure to use and why), then the implementation with clean code, and finally complexity analysis. This helps you think clearly even under pressure.
Does Phantom Code work for the coding platforms used in Count Number of Texts interviews?
Yes. Phantom Code works with all major coding platforms including LeetCode, HackerRank, CodeSignal, CoderPad, HackerEarth, and any browser-based coding environment.
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