Given a palindromic string s of lowercase English letters, change exactly one character to obtain a new string that is not a palindrome and is lexicographically smallest among all such possibilities. If no such string exists, return an empty string. Explain your algorithm, prove correctness, and analyze time and space complexity. Provide code in your preferred language.

def solution(s): n = len(s) if n == 1: return "" chars = list(s) # Make the earliest possible character as small as possible. # We only need to inspect the first half; changing a non-middle # character there to 'a' will break the palindrome. for i in range(n // 2): if chars[i] != 'a': chars[i] = 'a' return ''.join(chars) # If the first half is all 'a', the smallest valid change is to # increase the last character to 'b'. chars[-1] = 'b' return ''.join(chars)

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This is a Medium difficulty Coding & Algorithms question, commonly asked during Take-home Project rounds at Akuna Capital.

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Break a palindrome to smallest non-palindrome | Akuna Capital Coding Question

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This question evaluates string manipulation, lexicographic ordering, and algorithmic reasoning, including careful edge-case handling and time and space complexity analysis. Commonly asked in the Coding & Algorithms domain, it assesses practical application of algorithm design and correctness reasoning with emphasis on conceptual understanding and complexity trade-offs.

Medium
Akuna Capital
Coding & Algorithms
Software Engineer

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Break a palindrome to smallest non-palindrome

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