luogu_1006 传纸条

Posted 2020-09-24 Code_Together

 //和luogu1004一毛一样有木有

 

#include<bits/stdc++.h>

using namespace std;

int n,m,ans[60][60],a[60][60][60][60];

int max(int a,int b,int c,int d){

return max(max(a,b),max(c,d));

}

int main(){

scanf("%d%d",&n,&m);

for(int i=1;i<=n;i++)

for(int j=1;j<=m;j++)scanf("%d",&ans[i][j]);

for(int i=1;i<=n;i++)

for(int j=1;j<=m;j++)

for(int k=1;k<=n;k++)

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

a[i][j][k][l]=max(a[i][j-1][k][l-1],a[i-1][j][k-1][l],a[i-1][j][k][l-1],a[i][j-1][k-1][l])+ans[i][j]+ans[k][l];

if(i==k && j==l)a[i][j][k][l]-=ans[i][j];

}

cout<<a[n][m][n][m]<<endl;

return 0;

}