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How to Solve Replace Question Marks in String to Minimize Its Value Problem
Master the Replace Question Marks in String to Minimize Its Value LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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Medium#3081
LeetCode ProblemReplace Question Marks in String to Minimize Its Value
You are given a string s. s[i] is either a lowercase English letter or '?'. For a string t having length m containing only lowercase English letters, we define the function cost(i) for an index i as the number of characters equal to t[i] that appeared before it, i.e. in the range [0, i - 1]. The value of t is the sum of cost(i) for all indices i. For example, for the string t = "aab": Your task is to replace all occurrences of '?' in s with any lowercase English letter so that the value of s is minimized. Return a string denoting the modified string with replaced occurrences of '?'. If there are multiple strings resulting in the minimum value, return the lexicographically smallest one.
Hash TableStringGreedySortingHeap (Priority Queue)Counting
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Problem Breakdown
Understanding the Replace Question Marks in String to Minimize Its Value Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
You are given a string s. s[i] is either a lowercase English letter or '?'. For a string t having length m containing only lowercase English letters, we define the function cost(i) for an index i as the number of characters equal to t[i] that appeared before it, i.e. in the range [0, i - 1]. The value of t is the sum of cost(i) for all indices i. For example, for the string t = "aab": Your task is to replace all occurrences of '?' in s with any lowercase English letter so that the value of s is minimized. Return a string denoting the modified string with replaced occurrences of '?'. If there are multiple strings resulting in the minimum value, return the lexicographically smallest one.
MediumProblem #3081
LeetCodeReplace Question Marks in String to Minimize Its Value
Related Topics
Hash TableStringGreedySortingHeap (Priority Queue)Counting
How Phantom Code AI Helps
Get real-time assistance for Replace Question Marks in String to Minimize Its Value problems during coding interviews. Phantom Code AI provides instant solutions and explanations.
Examples
# Example 1
Input
s = "???"
Output
"abc"
# Example 2
Input
s = "a?a?"
Output
"abac"
Constraints
1 <= s.length <= 105
s[i] is either a lowercase English letter or '?'.
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Solve Replace Question Marks in String to Minimize Its Value — You are given a string s. s[i] is either a lowercase English letter or '?'. For ...
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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Frequently Asked Questions
Common questions about solving Replace Question Marks in String to Minimize Its Value and using Phantom Code AI during coding interviews.
How does Phantom Code AI help me solve coding problems like Replace Question Marks in String to Minimize Its Value during interviews?
Phantom Code AI 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 Replace Question Marks in String to Minimize Its Value?
Phantom Code AI 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 AI help me communicate my solution for problems like Replace Question Marks in String to Minimize Its Value?
Yes. Phantom Code AI 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 AI assist with different programming languages for Replace Question Marks in String to Minimize Its Value type problems?
Phantom Code AI 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 AI help me avoid during Replace Question Marks in String to Minimize Its Value interviews?
Phantom Code AI 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 AI detectable when solving problems like Replace Question Marks in String to Minimize Its Value during live interviews?
No. Phantom Code AI 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 AI help when I'm struggling with Replace Question Marks in String to Minimize Its Value 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 AI work for the coding platforms used in Replace Question Marks in String to Minimize Its Value interviews?
Yes. Phantom Code AI works with all major coding platforms including LeetCode, HackerRank, CodeSignal, CoderPad, HackerEarth, and any browser-based coding environment.
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