luogu 1605 迷宫

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;
const int N=6;
const int xd[]={0,-1,0,1};
const int yd[]={-1,0,1,0};

int n,m,k;
int strx,stry,endx,endy;
int _x,_y;
bool vis[N][N];
int answer;
bool all[N][N];

inline int read()
{
    int x=0;char c=getchar();
    while(c<‘0‘||c>‘9‘)c=getchar();
    while(c>=‘0‘&&c<=‘9‘)x=x*10+c-‘0‘,c=getchar();
    return x;
}

void dfs(int x,int y)
{
    vis[x][y]=1;
    if(x==endx&&y==endy)
    {
        answer++;
        return ;
    }
    for(int i=0;i<4;i++)
    {
        int xx=x+xd[i];
        int yy=y+yd[i];
        if(xx>0&&xx<=n&&yy>0&&yy<=m&&!vis[xx][yy])
        {
            dfs(xx,yy);
            vis[xx][yy]=0;
        }
    }
}

int main()
{
    n=read(),m=read(),k=read();
    strx=read(),stry=read(),endx=read(),endy=read();
    while(k--)
    {
        _x=read();
        _y=read();
        vis[_x][_y]=1;
    }
    dfs(strx,stry);
    printf("%d",answer);
    return 0;
}