搜索

见破题：

思路十分简单，至于代码嘛...反正我是改了一上午...

这里就想说一个搜索的通用方法，可以用f[i][j]表示某个状态，然后如果搜索到相同的坐标，但价值没有之前存的好，就直接退出...

至于此题就是（i，j）点的最大价值...

#include<bits/stdc++.h>
#define max(a,b) (((a)>(b)?(a):(b)))
using namespace std;
int h,v,w,qx,qy,zx,zy,dx[5]={1,2,3,4},d,f[50][50][5],ans;//f[i][j]表示到（i，j）点的最大速度. 
char ch[50][50];//1-左，2-右 
inline int read()
{
    int x=0,ff=1;
    char ch=getchar();
    while(!isdigit(ch)){if(ch=='-') ff=-1;ch=getchar();}
    while(isdigit(ch)) {x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}
    return x*ff; 
}
inline void dfs(int x,int y,int d,int v,int m)
{
    //printf("x=%d y=%d d=%d v=%d
",x,y,d,v);
    if(v<=f[x][y][d]) return;f[x][y][d]=v;
    if(ch[x][y]=='F') return;
    if(d==1)
    {
        int pd=0;
        if(x-1>=1&&ch[x-1][y]!='.') pd=1,dfs(x-1,y,1,v+1,0);   
        if(m!=1&&y-1>=1&&ch[x][y-1]!='.') pd=1,dfs(x,y,4,max(0,v-35),1);
         if(m!=2&&y+1<=w&&ch[x][y+1]!='.') pd=1,dfs(x,y,2,max(0,v-40),2);
        if(!pd&&x+1<=h&&ch[x+1][y]!='.') dfs(x,y,3,0,0);
    }
    else if(d==2)
    {
        int pd=0;
        if(y+1<=w&&ch[x][y+1]!='.') pd=1,dfs(x,y+1,2,v+1,0);
        if(m!=1&&x-1>=1&&ch[x-1][y]!='.') pd=1,dfs(x,y,1,max(0,v-35),1);
        if(m!=2&&x+1<=h&&ch[x+1][y]!='.') pd=1,dfs(x,y,3,max(0,v-40),2);
        if(!pd&&y-1>=1&&ch[x][y-1]!='.') dfs(x,y,4,0,0);
    }
    else if(d==3)
    {
        int pd=0;
        if(x+1<=h&&ch[x+1][y]!='.')pd=1,dfs(x+1,y,3,v+1,0);
        if(m!=1&&y+1<=w&&ch[x][y+1]!='.')pd=1,dfs(x,y,2,max(0,v-35),1);
         if(m!=2&&y-1>=1&&ch[x][y-1]!='.')pd=1,dfs(x,y,4,max(0,v-40),2);
        if(!pd&&x-1>=1&&ch[x-1][y]!='.') dfs(x,y,1,0,0);
    }
    else if(d==4)
    {
        int pd=0;
        if(y-1>=1&&ch[x][y-1]!='.')pd=1,dfs(x,y-1,4,v+1,0);
        if(m!=1&&x+1<=h&&ch[x+1][y]!='.')pd=1,dfs(x,y,3,max(0,v-35),1);   
        if(m!=2&&x-1>=1&&ch[x-1][y]!='.')pd=1,dfs(x,y,1,max(0,v-40),2);
        if(!pd&&y+1<=w&&ch[x][y+1]!='.') dfs(x,y,2,0,0);
    }
}
int main()
{
    freopen("1.in","r",stdin);
    h=read();w=read();v=read();
    for(register int i=1;i<=h;++i)
        for(register int j=1;j<=w;++j)  
        {
            cin>>ch[i][j];
            if(ch[i][j]=='F') zx=i,zy=j;
            else if(ch[i][j]!='.'&&ch[i][j]!='#')
            {
                qx=i;qy=j;
                if(ch[i][j]=='N') d=1;
                else if(ch[i][j]=='E') d=2;
                else if(ch[i][j]=='S') d=3;
                else if(ch[i][j]=='W') d=4;
            }     
        }    
    for(register int i=1;i<=h;++i)
        for(register int j=1;j<=w;++j) 
            for(register int k=1;k<=4;k++) f[i][j][k]=-1e9;     
    dfs(qx,qy,d,v,0);    
    for(register int i=1;i<=4;++i) ans=max(ans,f[zx][zy][i]);
    printf("%d
",ans);
    return 0;
}