題目描述
把M個同樣的蘋果放在N個同樣的盤子里舅逸,允許有的盤子空著不放桌肴,問共有多少種不同的分法?(用K表示)5琉历,1坠七,1和1水醋,5,1 是同一種分法彪置。
輸入
每個用例包含二個整數(shù)M和N拄踪。0<=m<=10,1<=n<=10拳魁。<=n<=10<=m<=10
樣例輸入
7 3
樣例輸出
8
import java.util.Scanner;
public class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n1 = sc.nextInt();
int n2 = sc.nextInt();
System.out.println(getNum(n1,n2));
}
private static int getNum(int apple, int plane) {
// TODO Auto-generated method stub
if((apple<0)||(apple>10)||(plane<1)||(plane>10)){
return -1;
}
else if(apple==1||plane==1||apple==0){
return 1;
}
else if(apple<plane){
return getNum(apple, plane-1);
}
else{
return getNum(apple-plane, plane)+getNum(apple, plane-1);
}
}
}