显示代码纯文本
#include <bits/stdc++.h>
using namespace std;
int m,n,mx,my;
char s[110][110];
int mv[8][2]={{0,1},{1,0},{-1,0},{0,-1},{1,1},{-1,-1},{1,-1},{-1,1}};
int cnt=0;
bool check(int x,int y){
if(x>=1&&x<=n&&y>=1&&y<=m){
if(s[x][y]=='.')
return true;
else return false;
}else{
return false;
}
}
void print(){
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
cout<<s[i][j];
}
cout<<endl;
}
}
int bfs(int x,int y){
int day[110][110];
bool vis[110][110]={0};
/*
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
day[i][j]=-1;
}
}
*/
day[mx][my]=0;
queue<pair<int,int> > q;
q.push(make_pair(mx,my));
int nt=0;
nt++;
s[mx][my]='M';
while(!q.empty()){
pair<int,int> now=q.front();
q.pop();
//cout<<day[now.first][now.second]<<endl;
//print();
for(int i=0;i<8;i++){
pair<int,int> next=make_pair(now.first+mv[i][0],now.second+mv[i][1]);
if(check(next.first,next.second)){
day[next.first][next.second]=day[now.first][now.second]+1;
q.push(next);
nt++;
s[next.first][next.second]='M';
if(nt==cnt){
return day[next.first][next.second];
}
}
}
}
return -1;
}
int main(int argc, char** argv) {
freopen("milkweed.in","r",stdin);
freopen("milkweed.out","w",stdout);
cin>>m>>n>>mx>>my;
for(int i=n;i>=1;i--){
for(int j=1;j<=m;j++){
cin>>s[i][j];
if(s[i][j]=='.'){
cnt++;
}
}
}
cout<<bfs(mx,my);
return 0;
}