求大佬救救 555

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 500;
int n, m;
int X1, Y1;//起点坐标
int dx[] = { -1,-2,-2,-1,1,2,2,1 };
int dy[] = { 2,1,-1,-2,2,1,-1,-2 };
bool vis[N][N];
int f[N][N];//步数数组

struct ma
{
	int x; int y;
};

void bfs(ma a)
{
	queue <ma>q; q.push(a);

	while (!q.empty())
	{
		int x = q.front().x;
		int y = q.front().y;
		q.pop();

		for (int i = 0; i <= 7; i++)
		{
			int xx = x + dx[i]; int yy = y + dy[i];

			if (xx > 0 && yy > 0 && xx <= n && yy <= m && vis[xx][yy] == 0)//在地图内 且未被遍历过
			{
				vis[xx][yy] = 1;
				f[xx][yy] = f[x][y] + 1;
				q.push({ xx,yy });
			}

		}
	}

}

int main()
{
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	memset(f, -1, sizeof(f));
	cin >> n >> m;
	cin >> X1 >> Y1;

	ma a = { X1,Y1 };
	f[X1][Y1] = 0;
	vis[X1][Y1] = 1;
	bfs(a);

	for (int i = 1; i <= n; i++)
	{
		for (int j = 1; j <= m; j++)
		{
			 printf("%-5d", f[i][j]);
		}
		cout << '\n';
	}
	return 0;
}