题解 | #放苹果#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int a = sc.nextInt();
            int b = sc.nextInt();
            int[][] dp = new int[a + 1][b + 1]; //定义动规数组
//             for (int j = 0; j <= a; j++) {
//                 dp[j][0] = 1;
//             }
            for (int j = 0; j <= b; j++) {
                dp[0][j] = 1;
            }
            dp[0][0] = 0;
            for (int i = 1; i <= a; i++) {
                for (int j = 1; j <= b; j++) {
                    if (i < j) {
                        //增加一个盘，如果苹果数小于盘子数，则怎么摆都有空盘，摆法不变
                        dp[i][j] = dp[i][j - 1];
                    } else {
                        //此盘为空 + 所有盘都不为空的摆法（i-j 的意思每个盘里先摆一个，剩下的再摆到j个盘里）
                        dp[i][j] = dp[i][j - 1] + dp[i - j][j];
                    }


                }
            }
            System.out.println(dp[a][b]);
        }
    }
}