@[zhaoyikuan](/user/1409685) $1 \le n \le 10^3$
by zhouzihang1 @ 2024-08-29 14:20:41
你数组倒是开大点啊！
by known_error_ @ 2024-08-29 14:21:55
```cpp
#include <iostream>
#include <queue>
using namespace std;
int a[1005][1005], flag[1005][1005];
int di[4] = {-1, 0, 1, 0}, dj[4] = {0, 1, 0, -1};
int sx, sy, ex, ey, n;
void bfs()
{
queue<int> qi, qj;
qi.push(sx);
qj.push(sy);
flag[sx][sy] = 0;
while (!qi.empty())
{
int i = qi.front();
int j = qj.front();
for (int k = 0; k < 4; k++)
{
int x = i + di[k];
int y = j + dj[k];
if (x >= 1 && x <= n && y >= 1 && y <= n && a[x][y] == 0 && flag[x][y] == -1)
{
qi.push(x);
qj.push(y);
flag[x][y] = flag[i][j] + 1;
}
}
qi.pop();
qj.pop();
}
}
int main()
{
string v;
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> v;
for (int j = 1; j <= n; j++)
{
a[i][j] = v[j - 1] - '0';
}
}
cin >> sx >> sy >> ex >> ey;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
flag[i][j] = -1;
bfs();
cout << flag[ex][ey] << endl;
return 0;
}
```
by known_error_ @ 2024-08-29 14:22:51
谢谢大佬！
by zhaoyikuan @ 2024-08-29 14:27:34