题解 | #走方格的方案数#

import java.io.*;

// 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) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str;
        while((str = br.readLine()) != null){
            String[] strs = str.split(" ");
            int m = Integer.parseInt(strs[0]);
            int n = Integer.parseInt(strs[1]);

            int[][] arr = new int[m+1][n+1];
            for(int i  = 0; i <=m;i++ ){
                arr[i][0] = 1;
            }

            for(int j = 0; j<= n ;j++){
                arr[0][j] = 1;
            }

            for(int i =1;i <= m;i++){
                for(int j = 1;j <= n;j++){
                    arr[i][j] = arr[i-1][j] + arr[i][j-1];
                }
            }
            System.out.println(arr[m][n]);
        }
    }
}