弱鸡一个，哪位大神帮忙优化一下

解题思路:

注意事项:

参考代码:

import java.util.Scanner;

public class Main {

private static int[][] step=new int[][]{{1,0},{0,1}};

private static int[][] v=new int[52][52];

private static int max=0;

private static int[][] step2=new int[][]{{-1,0},{0,-1}};

public static void main(String[] args) {

Scanner input=new Scanner(System.in);

int m=input.nextInt();

int n=input.nextInt();

int a[][]=new int[m+1][n+1];

for (int i = 1; i <=m; i++) {

for (int j = 1; j <=n; j++) {

a[i][j]=input.nextInt();

}

}

dfs(1,1,m,n,a,0);

System.out.println(max);

}

private static void dfs(int x, int y, int m, int n, int[][] a, int mun) {

if(x==m&&y==n){

v[m][n]=0;

dfs2(m,n,1,1,a,mun);

}else{

for (int i = 0; i <2; i++) {

int x1=x+step[i][0];

int y1=y+step[i][1];

if(x1>m||y1>n)continue;

if(v[x1][y1]==0){

v[x1][y1]=1;

dfs(x1,y1,m,n,a,mun+a[x1][y1]);

  v[x1][y1]=0;

}

}

}

}

private static void dfs2(int x, int y, int m, int n, int[][] a, int mun) {

if(x==m&&y==n){

if(max<mun)max=mun;

return;

}else{

for (int i = 0; i <2; i++) {

int x1=x+step2[i][0];

int y1=y+step2[i][1];

if(x1<1||y1<1)continue;

if(v[x1][y1]==0){

v[x1][y1]=1;

dfs2(x1,y1,m,n,a,mun+a[x1][y1]);

  v[x1][y1]=0;

}

}

}

}

}