本文共 5512 字，大约阅读时间需要 18 分钟。

Day1前挖的坑现在才补好…

就是一个三进制描述状态..

#include
   
    #include
    
     #include
     
      using namespace std;char c;bool flag;inline void read(int &a){    a=0;do c=getchar();while(c!='-'&&(c<'0'||c>'9'));    if(c=='-')flag=true,c=getchar();    while(c<='9'&&c>='0')a=(a<<3)+(a<<1)+c-'0',c=getchar();    if(flag)flag=false,a=-a;}int V[103][13];int n,m;const  int INF=1<<29;int f[102][9][3000];bool us[102][9];int Div[9];int getpc(int x,int pos){  return (x/Div[pos])%3;}    int pc(int pos,int op){  return op*Div[pos];}int get1(int x,int pos){    int l=x%Div[pos];    if(!l)return -1;    while(l
      
       m)        return -1;    return l/3==1?-1:pos;}int main(){    int i,j,t;    read(n),read(m);    Div[0]=1;    for(int i=1;i<=8;i++)       Div[i]=Div[i-1]*3;    for(i=1;i<=n;i++)      for(j=1;j<=m;j++)        read(V[i][j]);    int base;    int Lim=3;    for(int i=1;i<=m;i++)        Lim*=3;    Lim--;    int ans=-INF;    for(i=0;i<=n;i++)     for(j=0;j<=m;j++)      for(t=0;t<=2999;t++)        f[i][j][t]=-INF;    for(i=1;i<=n;i++)        for(j=1;j<=m;j++)            for(t=0;t<=Lim;t++)            {                if(i==3&&j==2&&t==567)                    t++,t--;                int rightpc=t%3,lowpc=getpc(t,j);                if(t==0){f[i][j][t]=0;continue;}                else                {                    if(i==1&&j==1)                        if(t^5)continue;                        else f[i][j][t]=V[i][j];                    else if(i==1)                    {                     if(lowpc==0)                            if(rightpc==0)                                f[i][j][t]=f[i][j-1][t];                            else if(rightpc==1)                                f[i][j][t]=f[i][j-1][t]+V[i][j];                            else                                 f[i][j][t]=f[i][j-1][t]+V[i][j];                        else if(lowpc==1)                            if(rightpc==0)                                f[i][j][t]=f[i][j-1][t-1*Div[j]+1]+V[i][j];                            else if(rightpc==1)                                f[i][j][t]=-INF;                            else                                f[i][j][t]=f[i][j-1][t-2-Div[j]]+V[i][j];                        else                            if(rightpc==0)                                f[i][j][t]=f[i][j-1][t-2*Div[j]+2]+V[i][j];                            else if(rightpc==1)                                f[i][j][t]=-INF;                            else                                 f[i][j][t]=-INF;                     }                    else if(j==1)                    {                        if(lowpc==0)                            if(rightpc==0)                                f[i][j][t]=f[i-1][m][t];                            else if(rightpc==1)                                f[i][j][t]=f[i-1][m][t-1+Div[j]]+V[i][j];                            else                                 f[i][j][t]=f[i-1][m][t-2+2*Div[j]]+V[i][j];                        else if(lowpc==1)                            if(rightpc==0)                                f[i][j][t]=f[i-1][m][t]+V[i][j];                            else if(rightpc==1)                                f[i][j][t]=-INF;                            else                                f[i][j][t]=f[i-1][m][t-2-Div[j]]+V[i][j];                        else                            if(rightpc==0)                                f[i][j][t]=f[i-1][m][t]+V[i][j];                            else if(rightpc==1)                                f[i][j][t]=-INF;                            else                                 f[i][j][t]=-INF;                    }                    else                    {                        if(lowpc==0)                            if(rightpc==0)                                {                                int p1=get1(t,j),p2=get2(t,j);                                f[i][j][t]=f[i][j-1][t];                                if(p1!=-1)                                    f[i][j][t]=max(f[i][j][t],f[i][j-1][t-Div[p1]+2+Div[j]*2]+V[i][j]);                                if(p2!=-1)                                    f[i][j][t]=max(f[i][j][t],f[i][j-1][t+Div[p2]+1+Div[j]*1]+V[i][j]);                                f[i][j][t]=max(f[i][j][t],f[i][j-1][t+2+Div[j]*1]+V[i][j]);;                                }                            else if(rightpc==1)                                f[i][j][t]=max(f[i][j-1][t],f[i][j-1][t-1+Div[j]])+V[i][j];                            else                                 f[i][j][t]=max(f[i][j-1][t],f[i][j-1][t-2+2*Div[j]])+V[i][j];                        else if(lowpc==1)                            if(rightpc==0)                                f[i][j][t]=max(f[i][j-1][t],f[i][j-1][t-1*Div[j]+1])+V[i][j];                            else if(rightpc==1)                                f[i][j][t]=-INF;                            else                                f[i][j][t]=f[i][j-1][t-2-Div[j]]+V[i][j];                        else                            if(rightpc==0)                                f[i][j][t]=max(f[i][j-1][t],f[i][j-1][t-2*Div[j]+2])+V[i][j];                            else if(rightpc==1)                                f[i][j][t]=-INF;                            else                                 f[i][j][t]=-INF;                    }                }            }       for(i=2;i<=n;i++)        for(j=2;j<=m;j++)            ans=max(ans,f[i][j-1][1+2*Div[j]]+V[i][j]);   printf("%d\n",ans);    return 0;}