#1316
Distinct Echo Substrings
hard · verified · 53% accepted · 337 likes · top 44%
string · trie · rolling hash · hash function
Description
Return the number of distinct non-empty substrings of text that can be written as the concatenation of some string with itself (i.e. it can be written as a + a where a is some string).
Example 1:
Input: text = "abcabcabc"
Output: 3
Explanation: The 3 substrings are "abcabc", "bcabca" and "cabcab".
Example 2:
Input: text = "leetcodeleetcode"
Output: 2
Explanation: The 2 substrings are "ee" and "leetcodeleetcode".
Solution