How should I practice Merging Palindromes?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Zscaler phone screen problems in FastPrep.

Is Merging Palindromes associated with Zscaler?

FastPrep tags this as a Zscaler phone screen coding practice problem when the problem catalog has that company and stage context.

Merging Palindromes

Zscaler● MediumINTERNPHONE SCREEN

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Problem statement

From the letters of first, choose a multiset that can be rearranged into a palindrome. Do the same independently for second. Combine the two chosen multisets and rearrange them into one palindrome.

Return the longest palindrome obtainable this way. If several have maximum length, return the lexicographically smallest.

Function

mergingPalindromes(first: String, second: String) → String

Examples

Example 1

first = "aabbc"second = "ddefefq"return = "abdefcfedba"

Use all available pairs and the smallest usable center. The result has maximum length and is lexicographically smallest among maximum-length results.

Example 2

first = "abc"second = "xyz"return = "a"

No pair is available. Choose the smallest single character as the center.

Constraints

1 <= first.length, second.length <= 200000
Both strings contain lowercase English letters only.