mes nbsp span pac using std for esp names

//和luogu1004一毛一樣有木有

#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;}

luogu_1006 傳紙條