题解

#include<iostream>
using namespace std;
int nx[]{1,0,-1,0},ny[]{0,-1,0,1};
int n,m,c,x1,y3,x2,y2,ans;
int a[6][6];
bool vis[6][6];
void dfs(int x,int y){
    if(x==x2&&y==y2){
        ans++;
        return;
    }
    for(int i=0;i<4;i++){
        int sx=x+nx[i],sy=y+ny[i];
        if(sx>=1&&sx<=n&&sy>=1&&sy<=m&&!vis[sx][sy]&&!a[sx][sy]==1){
            vis[sx][sy]=1;
            dfs(sx,sy);
            vis[sx][sy]=0;
        }
    }
    return;
}
int main(){
    cin>>n>>m>>c;
    cin>>x1>>y3>>x2>>y2;
    for(int i=1;i<=c;i++){
        int x,y;
        cin>>x>>y;
        a[x][y]=1;
    }
    vis[x1][y3]=1;
    dfs(x1,y3);
    cout<<ans;
}