hdoj-1570A C

A C

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 5689    Accepted Submission(s): 3700

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

2A 10 10C 4 2

 

Sample Output

36288006

 

题目链接

公式都给了，那就套公式吧。

#include<iostream>#include<cstdio>using namespace std;int jc(int n){    int sum=1;    for(int i=1;i<=n;i++)        sum*=i;    return sum;}int A(int m,int n){    return jc(n)/jc(n-m);}int C(int m,int n){    return A(m,n)/jc(m);}int main(){    char c;    int t,m,n;    scanf("%d",&t);    while(t--)    {        getchar();        scanf("%c%d%d",&c,&n,&m);        if(c=='A')            printf("%d\n",A(m,n));        else            printf("%d\n",C(m,n));    }    return 0;}