TheLongPalindrome | Topcoder Archive

Problem Statement

John and Brus are studying string theory at the university. Their task is to create a list of all the palindromes that contain between 1 and n lowercase letters ('a'-'z'), inclusive. A palindrome is a string that reads the same forward and backward. Additionally, each palindrome in their list must contain no more than k distinct letters. Return the number of palindromes in the list modulo 1234567891.

Definition

Class:: TheLongPalindrome
Method:: count
Parameters:: int, int
Returns:: int
Method signature:: int count(int n, int k)
(be sure your method is public)

Constraints

n will be between 1 and 1,000,000,000, inclusive.
k will be between 1 and 26, inclusive.

Examples

```
1
```
```
1
```
```
Returns: 26
```
All palindromes in the list are single character strings.
```
2
```
```
10
```
```
Returns: 52
```
Now we have single and double character palindromes.
```
3
```
```
2
```
```
Returns: 728
```
A slightly longer list.
```
44
```
```
7
```
```
Returns: 240249781
```

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