1100: 求组合数(函数专题)
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner cin = new Scanner(System.in);int m=cin.nextInt();int k=cin.nextInt();int result=fact(m)/(fact(k)*fact(m-k));System.out.println(result);}public static int fact(int n){
int ans=1;for(int i=2;i<=n;i++) ans*=i;return ans;}
}