Largest Odd Number in String
You are given a string num, representing a large integer. Return the largest-valued odd integer as a string that is a non-empty substring of num, or an empty string "" if no odd integer exists.
A substring is a contiguous sequence of characters within a string.
Example 1
Input
num = "52"Output
"5"The only non-empty substrings are "5", "2", and "52", and "5" is the only odd number.
Example 2
Input
num = "4206"Output
""There are no odd numbers in "4206".
Constraints
- 1 <= num.length <= 10^5
- num only consists of digits and does not contain any leading zeros.