题解 P2226 【[HNOI2001]遥控赛车比赛】

题目link
BFS，半裸题？(关于码风？我真的不是故意的才怪)

#include<bits/stdc++.h>
#define CHECK if(x>n||y>m||x<1||y<1||!s[x][y]||(x==sx&&y==sy))
#define FX int fx[4][2]={{1,0},{0,1},{-1,0},{0,-1}};
#define INT int n,m,sx,sy,ex,ey,s[110][110],dis[110][110][4],f[110][110][4],res;
#define NODE struct node{int x,y,z;};
#define FRE freopen("Racing.in","r",stdin);freopen("Racing.out","w",stdout);
#define FIRST_PUSH while(!q.empty()){q.pop();}for(int i=0;i<=3;i++){q.push((node){sx,sy,i});}
#define INPUT scanf("%d%d",&n,&m);scanf("%d%d%d%d",&sx,&sy,&ex,&ey);for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){scanf("%d",&s[i][j]);}}
#define WORK for(int i=1;i<=10;i++){memset(f,0,sizeof(f));memset(dis,0,sizeof(dis));res=BFS(i);if(res==-1){break;}printf("%d %d\n",i,res);}
using namespace std;
FX
INT
NODE
int BFS(int X)
{
    queue<node>q;
    FIRST_PUSH
    f[sx][sy][0]=0;
    f[sx][sy][1]=0;
    f[sx][sy][2]=0;
    f[sx][sy][3]=0;
    while(!q.empty())
    {
        node now=q.front();
        q.pop();
        for(int i=0;i<4;i++)
        {
            int x=now.x+fx[i][0];
            int y=now.y+fx[i][1];
            CHECK
            {
            	continue;
            }
            int a=0;
            if(i==now.z)
            {
            	a=min(X,f[now.x][now.y][now.z]+1);
            }
            else
            {
                if(f[now.x][now.y][now.z]!=X)
                {
                	continue;
                }
                a=1;
            }
            if(dis[x][y][i]&&a<=f[x][y][i])
            {
            	continue;
            }
            f[x][y][i]=a;
            q.push((node){x,y,i});
            dis[x][y][i]=dis[now.x][now.y][now.z]+1;
            if(x==ex&&y==ey)
            {
                return dis[x][y][i];
            }
        }
    }
    return -1;
}
int main()
{
    //FRE
    INPUT
    WORK
}