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 .
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)
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.
#include<iostream>
using namespace std;
int fac(int k)
{
int sum=1;
for(int i=1;i<=k;i++)
sum*=i;
return sum;
}
int main()
{
int n,N,M;
char ch;
cin>>n;
while(n--)
{
cin>>ch>>N>>M;
if(ch=='A')
cout<<fac(N)/(fac(N-M))<<endl;
else if(ch=='C')
cout<<fac(N)/(fac(M)*fac(N-M))<<endl;
}
return 0;
}
