NOIP2008 传纸条

Posted 2020-10-11

#include <bits/stdc++.h>
#define max4(a,b,c,d) max(max((a),(b)),max((c),(d)))
using namespace std;
int like[55][55],dp[55][55][55][55];
int main(){
int n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            cin>>like[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 y=1;y<=m;y++)
                    if(i==k&&y==j&&(i!=n||j!=m))
                        continue;
                    else
                        dp[i][j][k][y]=like[i][j]+like[k][y]+max4(dp[i-1][j][k-1][y],
                                                                     dp[i][j-1][k-1][y],
                                                                     dp[i-1][j][k][y-1],
                                                                       dp[i][j-1][k][y-1]);
    cout<<dp[n][m][n][m];
    return 0;
}