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How to Solve Count Words Obtained After Adding a Letter Problem
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Start Free for WindowsMedium#2135
LeetCode ProblemCount Words Obtained After Adding a Letter
You are given two 0-indexed arrays of strings startWords and targetWords. Each string consists of lowercase English letters only. For each string in targetWords, check if it is possible to choose a string from startWords and perform a conversion operation on it to be equal to that from targetWords. The conversion operation is described in the following two steps: Return the number of strings in targetWords that can be obtained by performing the operations on any string of startWords. Note that you will only be verifying if the string in targetWords can be obtained from a string in startWords by performing the operations. The strings in startWords do not actually change during this process.
ArrayHash TableStringBit ManipulationSorting
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Problem Breakdown
Understanding the Count Words Obtained After Adding a Letter Problem
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Problem Statement
You are given two 0-indexed arrays of strings startWords and targetWords. Each string consists of lowercase English letters only. For each string in targetWords, check if it is possible to choose a string from startWords and perform a conversion operation on it to be equal to that from targetWords. The conversion operation is described in the following two steps: Return the number of strings in targetWords that can be obtained by performing the operations on any string of startWords. Note that you will only be verifying if the string in targetWords can be obtained from a string in startWords by performing the operations. The strings in startWords do not actually change during this process.
MediumProblem #2135
LeetCodeCount Words Obtained After Adding a Letter
Related Topics
ArrayHash TableStringBit ManipulationSorting
How Phantom Code Helps
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Examples
# Example 1
Input
startWords = ["ant","act","tack"], targetWords = ["tack","act","acti"]
Output
2
# Example 2
Input
startWords = ["ab","a"], targetWords = ["abc","abcd"]
Output
1
Constraints
1 <= startWords.length, targetWords.length <= 5 * 104
1 <= startWords[i].length, targetWords[j].length <= 26
Each string of startWords and targetWords consists of lowercase English letters only.
No letter occurs more than once in any string of startWords or targetWords.
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Solve Count Words Obtained After Adding a Letter — You are given two 0-indexed arrays of strings startWords and targetWords. Each s...
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def solve(input):
# Optimal O(n) solution
return result
Time: O(n) | Space: O(n)
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Frequently Asked Questions
Common questions about solving Count Words Obtained After Adding a Letter and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Count Words Obtained After Adding a Letter 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 Words Obtained After Adding a Letter?
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.
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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.
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What coding mistakes does Phantom Code help me avoid during Count Words Obtained After Adding a Letter 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 Words Obtained After Adding a Letter during live interviews?
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How does Phantom Code help when I'm struggling with Count Words Obtained After Adding a Letter 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 Words Obtained After Adding a Letter 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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