(HDU)1570 -- A C
题目链接:https://vjudge.net/problem/HDU-1570
1 #include <cstdio> 2 #include <cstring> 3 #include <cmath> 4 #include <iostream> 5 #include <algorithm> 6 #include <string> 7 #include <cstdlib> 8 9 using namespace std; 10 11 int f(int n) 12 { 13 if(n==0||n==1) return 1; 14 return n*f(n-1); 15 } 16 17 int c(int m,int n) 18 { 19 return f(n)/(f(m)*f(n-m)); 20 } 21 22 int a(int m,int n) 23 { 24 return f(n)/f(n-m); 25 } 26 27 int main() 28 { 29 int t,n,m; 30 char ch; 31 scanf("%d",&t); 32 while(t--) 33 { 34 getchar(); 35 scanf("%c %d %d",&ch,&n,&m); 36 if(ch=='A') printf("%d\n",a(m,n)); 37 if(ch=='C') printf("%d\n",c(m,n)); 38 } 39 }