TYVJ 1330 乳草的入侵

#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<iostream>
#define LL long long
#define db double
#define maxn 10000000
#define max(a,b) ((a>b)?(a):(b))
#define min(a,b) ((a<b)?(a):(b))
using namespace std;
int n,m,bx,by;
bool mp[101][101];
int xx[8]={1,-1,1,-1,0,0,1,-1},yy[8]={1,-1,-1,1,1,-1,0,0};
struct data{
int x,y,step;
}q[10001];

bool judge(int x,int y){
if (mp[x][y]||x<1||y<1||x>m||y>n) return 0;
mp[x][y]=1;
return 1;
}
int bfs(int bx,int by){
int t=0,w=1;
int nowx,nowy;
q[0].x=bx; q[0].y=by;
mp[bx][by]=1;
while (t<w){
for (int i=0;i<8;i++){
nowx=q[t].x+xx[i];
nowy=q[t].y+yy[i];
if (judge(nowx,nowy)){
q[w].x=nowx;
q[w].y=nowy;
q[w].step=q[t].step+1;
w++;
}
}
t++;
}
printf("%d",q[w-1].step);
}
int main(){
scanf("%d%d%d%d",&n,&m,&bx,&by);
char ch[101];
for (int i=m;i>0;i--){
scanf("%s",ch);
for (int j=0;j<n;j++)
if (ch[j]=='*') mp[i][j+1]=1;
}
bfs(bx,by);
return 0;
}