Submit | All submissions | Best solutions | Back to list |
DORTMUND - Dortmund Dilemma |
Borussia Dortmund is a famous football (soccer) club from Germany. Apart from their fast style of playing, the thing that makes them unique is the hard to pronounce names of their players (Błaszczykowski, Papastathopoulos, Großkreutz etc.).
The team's coach is your friend. He is in a dilemma as he can't decide how to make it easier to call the players by name, during practice sessions. So, you advised him to assign easy names to his players. A name is easy to him if
- It consists of only lowercase English letters.
- Its length is exactly N.
- It contains exactly K different letters from the 26 letters of English alphabet.
- At least one of its proper prefixes matches with its proper suffix of same length.
Given, N and K you have to tell him the number of easy names he can choose from modulo (10^9+9).
Note : A prefix P of a name W is proper if, P ≠ W. Similarly, a suffix S of a name W is proper if, S ≠ W.
Input
The first line of the input will contain T ( the number of testcases ).
Each of the next T lines will contain two space separated integers N and K.
Output
For each testcase, output the number of ways the coach can assign names to his players modulo (10^9+9).
Constraints
1 ≤ T ≤ 105
1 ≤ N ≤ 105
1 ≤ K ≤ 26
Example
Input: 8
1 1
2 1
4 2
2 2
5 1
3 2
6 2
1 3 Output: 0
26
2600
0
26
650
13650
0
Added by: | Bidhan |
Date: | 2014-08-03 |
Time limit: | 3s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: WHITESPACE |
Resource: | Own problem from HackerRank |
hide comments
2024-03-14 13:20:54 Sushovan Sen
Wow! easy names with length 10^9 |
|
2016-02-14 15:21:21 Siddharth Singh
Solved It After A Month, Read A Lot To Solve Thing. Finalllyyyy!!!! BVB09 Always <3 |
|
2015-03-11 11:22:56 (Tjandra Satria Gunawan)(曾毅昆)
Warning: unusual modulo 10^9+9 not 10^9+7, cost me many WA (>_<) |