Longest Duplicate Substring
Given a string s, consider all duplicated substrings: contiguous substrings of s that occur 2 or more times. The occurrences may overlap.
Return any duplicated substring that has the longest possible length. If s does not have a duplicated substring, return "".
Example 1
Input
s = "banana"Output
"ana"The substring "ana" occurs more than once in "banana" and has the longest possible duplicated length.
Example 2
Input
s = "abcd"Output
""There is no substring in "abcd" that occurs 2 or more times, so the answer is the empty string.
Constraints
- 2 <= s.length <= 3 * 10^4
- s consists of lowercase English letters.