1570.A C

A C

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 5288 Accepted Submission(s): 3406

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

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int f(int n)
{
    int t=1,i;
    if(n==1)
    {
        return 1;
    }
    for(i=n;i>0;i--)
    {
        t=t*i;
    }
    return t;
}

int main()
{
    int t,m,n,s;
    char a;
    scanf("%d",&t);
    while(t--)
    {
        getchar();//代表回车，切记！！！
        scanf("%c%d%d",&a,&n,&m);
        if(a=='A')
        {
            s=f(n)/f(n-m);
        }
        else
        {
            s=f(n)/(f(m)*f(n-m));
        }
        printf("%d\n",s);
    }
    return 0;
}