P1101 单词方阵

传送门

dfs 搜索 不理解这个题 改了一遍才ac ,边界没处理好

#include <bits/stdc++.h>
using namespace std;
typedef long long ll ;
typedef double    dl ;
#define INF 0x7f

const int  inf = 987654321;
const int sz = 1e6 + 5;
const int mod = 1e9 + 7;
const int sqrtn = 300;

#define f(i,l,r) for(int i=l;i<=r;++i)
#define g(i,l,r) for(int i=l;i>=r;--i)
#define CLR(arr,val) memset(arr,val,sizeof(arr))
#define sz(a)   strlen(a)
#define FAST_IO ios::sync_with_stdio(false);cin.tie(0);

#define lowbit(x) x&(-x)
#define X first
#define Y second 

#define pb push_back
#define pii pair<int,int>

int dir[8][2]={{1,0},{-1,0},{0,1},{0,-1},{1,1},{1,-1},{-1,1},{-1,-1}};
int n;
char a [105][105];
int  vis [105][105];
char b[]="yizhong";
int len = sz(b);
int s ;
void rangecolor(int x,int y,int k)
{
    int dx =x  ;
    int dy =y ;
 
    f(i,1,len)
    {

          dx =dx - dir[k][0];
        dy =dy - dir[k][1];
        vis[dx][dy]=1;
    } 
}
void dfs(int x,int y,int k,int pos)
{
    if(pos<0||pos>n ) return;
    if(pos==len)
    { 
         rangecolor(x,y,k);
        return ;
    }
    if(a[x][y]==b[pos])
    {
        int dx =x + dir[k][0];
        int dy =y + dir[k][1];
        if(dx<0||dx>n+1||dy<0||dy>n+1) return ;
        dfs(dx,dy,k,pos+1); 
    }



}
void work()
{ 
    cin>>n;
    f(i,1,n)f(j,1,n)cin>>a[i][j];
    f(i,1,n)f(j,1,n)
    {
        if(a[i][j]=='y')
        {
            f(k,0,7)
                dfs(i,j,k,0);
        }
    }
 //   f(i,1,n)f(j,1,n) cout<<vis[i][j];
  
      f(i,1,n)
    {
         f(j,1,n)
         {
             if(vis[i][j])        cout<<a[i][j];
             else cout<<"*";
         }
         cout<<endl;
    }
  
}

int main()
{
    FAST_IO ;
    
    freopen("in","r",stdin);
    freopen("out","w",stdout);
    cout<<"hello"<<endl;
 
    work();
   
    return 0; 
}