Problem Description

Are you excited when you see the title “AC” ? If the answer is YES , AC it ;

You must learn these two combination formulas in the school . If you have forgotten it , see the picture.

Now I will give you n and m , and your task is to calculate the answer .

Input

In the first line , there is a integer T indicates the number of test cases. Then T cases follows in the T lines. Each case contains a character ‘A’ or ‘C’, two integers represent n and m. (1<=n,m<=10)

Output

For each case , if the character is ‘A’ , calculate A(m,n),and if the character is ‘C’ , calculate C(m,n). And print the answer in a single line.

Sample Input

2 A 10 10 C 4 2

Sample Output

3628800 6

题意：很简单，看图片就能理解了。

水题一个！就不多解释了。

import java.util.Scanner;public class Main{    public static void main(String[] args) {        Scanner sc = new Scanner(System.in);        int t = sc.nextInt();        while(t-->0){            String str = sc.next();            int n = sc.nextInt();            int m =sc.nextInt();            if(str.charAt(0)=='A'){                System.out.println(a(n,m));            }else{                System.out.println(c(n,m));            }        }    }    private static int c(int n, int m) {        int num =1;        if(n-m>m){            m=n-m;        }        int cnum=1;        for(int i=1;i<=n-m;i++){            cnum=cnum*i;        }        for(int i=m+1;i<=n;i++){            num=num*i;        }        return num/cnum;    }    private static int a(int n, int m) {        int num=1;        for(int i=n-m+1;i<=n;i++){            num=num*i;        }        return num;    }}