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Solution: Largest Odd Number in String

Explore how to find the largest odd-valued integer formed as a contiguous substring of a numeric string. This lesson guides you through using a greedy algorithm to scan from the end and extract the substring ending at the rightmost odd digit, ensuring an efficient O(n) time solution with constant space.

Statement

You are given a string, num, which represents a large integer. Your task is to find the largest odd-valued integer that can be formed as a non-empty substring of num. Return this odd integer as a string. If no odd integer exists, return an empty string ("").

Note: A substring is a continuous sequence of characters within a string.

Constraints:

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