spoj#AMR10J. Mixing Chemicals

Mixing Chemicals

There are N bottles each having a different chemical. For each chemical i, you have determined C[i] which means that mixing chemicals i and C[i] causes an explosion. You have K distinct boxes. In how many ways can you divide the N chemicals into those boxes such that no two chemicals in the same box can cause an explosion together?
 
INPUT
The first line of input is the number of test cases T. T test cases follow each containing 2 lines.
The first line of each test case contains 2 integers N and K.
The second line of each test case contains N integers, the ith integer denoting the value C[i]. The chemicals are numbered from 0 to N-1.
 
OUTPUT
For each testcase, output the number of ways modulo 1,000,000,007.
 
CONSTRAINTS
T <= 50
2 <= N <= 100
2 <= K <= 1000
0 <= C[i] < N
For all i, i != C[i]
 
SAMPLE INPUT
3
3 3
1 2 0
4 3
1 2 0 0
3 2
1 2 0
 
SAMPLE OUTPUT
6
12
0
 
EXPLANATION
In the first test case, we cannot mix any 2 chemicals. Hence, each of the 3 boxes must contain 1 chemical, which leads to 6 ways in total.
In the third test case, we cannot put the 3 chemicals in the 2 boxes satisfying all the 3 conditions.