spoj mgame

题解：

f[i][j]表示先后手最大差

g[i][j]表示在最大差的时候是否有后手没得走

代码：

#include<bits/stdc++.h>
using namespace std;
const int N=;
int n,m,q,x,y,a[N][N];
double f[N][N];
char s[];
int can(int x,int y){return x<=n&&y<=m&&a[x][y]>=;}
int main()
{
    scanf("%d%d",&n,&m);
    gets(s);
    for (int i=;i<=n;i++)
     {
        gets(s+);
        for (int j=;j<=m;j++)
         {
            if (s[j]=='.')a[i][j]=;
            if (s[j]=='#')a[i][j]=-;
            if (s[j]=='H'||s[j]=='C')a[i][j]=;
            if (s[j]=='F'||s[j]=='S')a[i][j]=;
            if (s[j]=='I'||s[j]=='B')a[i][j]=;
         }
     }
    for (int i=n;i;i--)
     for (int j=m;j;j--)
      if (a[i][j]>=)
       {
        int flag=;
        double z=-1e10;
        if (can(i,j+)) flag=,z=max(z,a[i][j+]-f[i][j+]);
        if (can(i+,j)) flag=,z=max(z,a[i+][j]-f[i+][j]);
        if (can(i+,j+)) flag=,z=max(z,a[i+][j+]-f[i+][j+]);
        f[i][j]=z;
        if (flag) f[i][j]=-0.5;
       }
    scanf("%d",&q);
    while (q--)
     {
        scanf("%d%d",&x,&y);
        printf("%s\n",f[x][y]>?"HAL":"DAVE");
     }
    return ;
}