@[For_Miku](/user/133116)
```
#include<iostream>
#include<queue>
#include<cstdio>
#include<queue>
#include<cstring>
using namespace std;
struct xy
{
int x;
int y;
int t;
};
queue < xy > q;
int vis[1001][1010];
char ma[1010][1010];
int mx[9] = { 0, 1, 1, 1, 0, -1, -1, -1 };
int my[9] = { 1, 1, 0, -1, -1, -1, 0, 1 };
int mx1[5] = { 0, 1, 0, -1 };
int my1[5] = { 1, 0, -1, 0 };
int n, m;
int xx, yy, xxx, yyy;
int f;
int cnt;
int main()
{
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; ++i)
{
for (int j = 1; j <= m; ++j)
cin >> ma[i][j];
}
while (scanf("%d%d%d%d", &xx, &yy, &xxx, &yyy))
{
cnt++;
if (!xx && !yy && !xxx && !yyy)
return 0;
f = 0;
vis[xx][yy] = cnt * 2;
for (int i = 0; i <= 7; ++i)
{
int u = xx + mx[i];
int v = yy + my[i];
while (1 <= u && u <= n && 1 <= v && v <= m && ma[u][v] == 'O')
{
vis[u][v] = cnt * 2;;
u += mx[i];
v += my[i];
}
}
if (vis[xxx][yyy] == cnt * 2)
{
cout << 0 << endl;
continue;
}
while (!q.empty())
q.pop();
q.push(xy{xxx, yyy, 0});
while (!q.empty())
{
int u = q.front().x;
int v = q.front().y;
int ut = q.front().t;
q.pop();
for (int i = 0; i <= 3; ++i)
{
int u1 = u + mx1[i];
int v1 = v + my1[i];
if (u1 < 1 || u1 > n || v1 < 1 || v1 > m)
continue;
if (vis[u1][v1] == cnt * 2 - 1)
continue;
if (vis[u1][v1] == cnt * 2)
{
f = 1;
cout << ut + 1 << endl;
break;
}
if (ma[u1][v1] == 'O')
{
vis[u1][v1] = cnt * 2 - 1;
q.push((xy){u1, v1, ut + 1});
}
}
if (f)
break;
}
if (!f)
printf("Poor Harry\n");
}
return 0;
}
```
有空请您访问我的 [CSDN博客](https://blog.csdn.net/metaphysis)，里面有我写的一本书，内有编程竞赛相关内容的介绍，并附有对应的练习题目（题目源自UVa OJ），可免费下载此书的PDF版本：[《C++，挑战编程——程序设计竞赛进阶训练指南》](https://blog.csdn.net/metaphysis/article/details/90288252)。
by metaphysis @ 2020-10-05 13:32:41
@[metaphysis](/user/333388) 不胜感激（呜呜呜）
by Xhesika_Frost @ 2020-10-05 14:00:45