Problem Description
You must be very familiar with derivative in math,and I guarantee that you can work out the derivative easily. Generally speaking,the last problem is the most difficult problem only a few can work out. However,it is not the case in this contest designed by Samuel. Give you 1 number n,and 2 extra numbers a and b you can work this problem out. For example,f(x)=ax^b,the 2 class derivative is f''=a*b*(b-1)x^(b-2),here n means n class. Here all the numbers are integers.
Input
The input consists 2 parts:
test case number t,each of the test case contains 3 number n(n>=0),a,b(a,b will not be very large),the original one is like the format of f(x)=ax^b.
Output
Output the a after n times' work.
Sample Input
2
1 2 3
3 4 5
Sample Output
6
240
https://blog.csdn.net/gnefniu/article/details/17500633
两组输入
1 2 3(n=1,a=2,b=3)
f(x)=2x^3
f'(x)=3*2x^2=6x^2，所以a=6
3 4 5(n=3,a=4,b=5)
f(x)=4x^5
f'(x)=5*4x^4=20x^4
f''(x)=4*20x^3=80x^3
f'''(x)=3*80x^2=240x^2，所以a=240
看出来没，a最后会等于a*b*(b-1)…(b-n+1)
如果你要编程
for i=0;i<n;i++
a=a*(b-i);
最后的a就是要输出的了
当然，这个只能应对函数是f(x)=ax^b，从你问题中不知道你要干嘛。