题号：NC14584
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 256 M，其他语言512 M
64bit IO Format: %lld
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 256 M，其他语言512 M
64bit IO Format: %lld
题目描述
Yuanyuan Long is a dragon like this picture?
I don’t know, maybe you can ask him. But I’m sure Yuanyuan Long likes ballons, he has a lot of ballons.
One day, he gets n white ballons and k kinds of pigment, and he thought a problem:
1. Number these ballons b1, b2, … , bi, …, to bn.
2. Link these ballons to a circle in order, and color these ballons.
3. He need to make sure that any neighbor ballons have different colors.
He wants to know how many solutions to solve this problem. Can you get the answer to him? The answer maybe very large, get the answer MOD 100000007.
For Example: with 3 ballons and 3 kinds of pigment
Your answer is 3*2*1 MOD 100000007 = 6.
The answer maybe large, you can use integer type long long.
输入描述:
The first line is the cases T. ( T <=
100)
For next T lines, each line contains n and
k. (2<= n <= 10000, 2<= k
<=100)
输出描述:
For each test case, output the answer on
each line.