- Difficulty: Hard
- Tags: LeetCode, Hard, String, Dynamic Programming, leetcode-2478, O(n * k), O(n), DP
Problem
You are given a string s
that consists of the digits '1'
to '9'
and two integers k
and minLength
.
A partition of s
is called beautiful if:
s
is partitioned intok
non-intersecting substrings.- Each substring has a length of at least
minLength
. - Each substring starts with a prime digit and ends with a non-prime digit. Prime digits are
'2'
,'3'
,'5'
, and'7'
, and the rest of the digits are non-prime.
Return the number of beautiful partitions of s
. Since the answer may be very large, return it modulo 109 + 7
.
A substring is a contiguous sequence of characters within a string.
Example 1:
Input: s = "23542185131", k = 3, minLength = 2 Output: 3 Explanation: There exists three ways to create a beautiful partition: "2354 | 218 | 5131" "2354 | 21851 | 31" "2354218 | 51 | 31"
Example 2:
Input: s = "23542185131", k = 3, minLength = 3 Output: 1 Explanation: There exists one way to create a beautiful partition: "2354 | 218 | 5131".
Example 3:
Input: s = "3312958", k = 3, minLength = 1 Output: 1 Explanation: There exists one way to create a beautiful partition: "331 | 29 | 58".
Constraints:
1 <= k, minLength <= s.length <= 1000
s
consists of the digits'1'
to'9'
.