题解 | #走方格的方案数#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        // while (in.hasNextInt()) { // 注意 while 处理多个 case
        //     int a = in.nextInt();
        //     int b = in.nextInt();
        //     System.out.println(a + b);
        // }
        int m = in.nextInt();
        int n = in.nextInt();

        int[][] dp = new int[m + 1][n + 1];
        for (int i = 1; i <= m; i++) {
            dp[i][1] = i + 1;
        }
        for (int i = 1; i <= n; i++) {
            dp[1][i] = i + 1;
        }
        for (int i = 2; i <= m; i++) {
            
            for (int j = 2; j <= n; j++) {
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
            }
        }
        System.out.print(dp[m][n]);
    }
}