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This is a medium difficulty Coding & Algorithms question, commonly asked during Technical Screen rounds at Microsoft.

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This question is commonly asked for Software Engineer candidates at Microsoft during technical interviews.

Check palindrome and find next larger palindrome

Q: Check palindrome and find next larger palindrome

This question evaluates proficiency in string and numeric manipulation, specifically palindrome detection and generation of the next strictly larger numeric palindrome from a large integer represented as a string.

Problem: Palindrome Check + Next Larger Palindrome

Part 1: Palindrome validation

Given a string s, determine whether s is a palindrome (reads the same forward and backward).

Return true if s is a palindrome, otherwise false .
Assume s contains only alphanumeric characters and is case-sensitive unless you explicitly normalize.

Part 2: Next larger palindrome number

Given a non-negative integer x (potentially very large), return the smallest palindrome number strictly greater than x.

Because x may exceed 64-bit range, treat x as a string.

Input/Output

Input: s (string) for Part 1; x (string representing a non-negative integer) for Part 2
Output: boolean for Part 1; string for Part 2

Constraints (assume for interview)

1 <= len(s) <= 2 * 10^5
1 <= len(x) <= 2 * 10^5
x has no leading zeros unless x == "0"

Examples

Part 1:

s = "racecar" -> true
s = "ab" -> false

Part 2:

x = "123" -> "131"
x = "99" -> "101"
x = "808" -> "818"

Problem: Palindrome Check + Next Larger Palindrome

Part 1: Palindrome validation

Given a string s, determine whether s is a palindrome (reads the same forward and backward).

Return true if s is a palindrome, otherwise false .

Assume s contains only alphanumeric characters and is case-sensitive unless you explicitly normalize.

Part 2: Next larger palindrome number

Given a non-negative integer x (potentially very large), return the smallest palindrome number strictly greater than x.

Because x may exceed 64-bit range, treat x as a string.

Input/Output

Input: s (string) for Part 1; x (string representing a non-negative integer) for Part 2

Output: boolean for Part 1; string for Part 2

Constraints (assume for interview)

1 <= len(s) <= 2 * 10^5

1 <= len(x) <= 2 * 10^5

x has no leading zeros unless x == "0"

Examples

Part 1:

s = "racecar" -> true

s = "ab" -> false

Part 2:

x = "123" -> "131"

x = "99" -> "101"

x = "808" -> "818"

Check palindrome and find next larger palindrome

Quick Overview

Problem: Palindrome Check + Next Larger Palindrome

Part 1: Palindrome validation

Part 2: Next larger palindrome number

Input/Output

Constraints (assume for interview)

Examples

Submit Your Answer to Earn 20XP

Check palindrome and find next larger palindrome

Quick Overview

Problem: Palindrome Check + Next Larger Palindrome

Part 1: Palindrome validation

Part 2: Next larger palindrome number

Input/Output

Constraints (assume for interview)

Examples

Submit Your Answer to Earn 20XP