题解 | #放苹果#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner fzhinput = new Scanner(System.in);
        int pgnum = fzhinput.nextInt();
        int pznum = fzhinput.nextInt();
        System.out.println(fppg(pgnum,pznum));
    }
    private static int fppg(int pg, int pz){
        int sz[][] = new int[pg+1][pz+1];
        for(int i=0;i<=pz;i++){
            sz[0][i]=1;
        }
        for(int i=0;i<=pg;i++){
            sz[i][1]=1;
        }

        for(int i=1;i<=pg;i++){
            for(int j=2;j<=pz;j++){
                if(i<j){
                    sz[i][j]=sz[i][i];
                }
                else{
                    sz[i][j]=sz[i-j][j]+sz[i][j-1];
                }
            }
        }
        return sz[pg][pz];
    }
}