2445: The only survival

内存限制:128 MB 时间限制:40.000 S
评测方式:文本比较 命题人:
提交:0 解决:0

题目描述

There is an old country and the king fell in love with a devil. The devil always ask the king to do some crazy things. Although the king used to be wise and beloved by his people. Now he is just like a boy in love and can’t refuse any request from the devil. Also, this devil is looking like a very cute Loli.

Something bad actually happen. The devil makes this kingdom's people infected by a disease called lolicon. Lolicon will take away people's life in silence. 

Although z*p is died, his friend, y*wan is not a lolicon. Y*wan is the only one in the country who is immune of lolicon, because he like the adult one so much. 

As this country is going to hell, y*wan want to save this country from lolicon, so he starts his journey.

You heard about it and want to help y*wan, but y*wan questioned your IQ, and give you a question, so you should solve it to prove your IQ is high enough.

The problem is about counting. How many undirected graphs satisfied the following constraints?

1. This graph is a complete graph of size n. 
2. Every edge has integer cost from 1 to L.
3. The cost of the shortest path from 1 to n is k.

Can you solve it?

output the answer modulo 10^9+7

输入

The first line contains an integer T, denoting the number of the test cases.
For each test case, the first line contains 3 integers n,k,L.

T<=5 n,k<=12,L<=10^9.

输出

For each test case, output the answer in one line.

样例输入 复制

2
3 3 3
4 4 4

样例输出 复制

8
668