洛谷P1443 马的遍历——广搜

#include<iostream>
#include<iomanip>
#include<cstdio>
#include<queue>
#include<cstring>
using namespace std;
int n, m, sx, sy;
int mp[410][410];
int xx[] = { 2,2, 1, 1,-1,-1,-2,-2 };
int yy[] = { 1,-1,2,-2, 2,-2,1,-1 };
struct node
{
  int x, y, s;
};
int main()
{
  cin >> n >> m >> sx >> sy;
  memset(mp, -1, sizeof(mp));
  queue<node>q;
  node t;
  t.x = sx; t.y = sy; t.s = 0;
  q.push(node{ sx,sy,0 });
  mp[sx][sy] = 0;
  while (!q.empty())
  {
    for (int i = 0; i < 8; i++)
    {
      int dx = xx[i] + q.front().x;
      int dy = yy[i] + q.front().y;
      if (dx >= 1 && dx <= n && dy >= 1 && dy <= m && mp[dx][dy] == -1)
      {
        q.push(node { dx, dy, q.front().s + 1 });
        mp[dx][dy] = q.front().s + 1;
      }
    }
    q.pop();
  }
  for (int i = 1; i <= n; i++)
  {
    for (int j = 1; j <= m; j++)
    {
      printf("-5%d", mp[i][j]);
    }
    cout << endl;
  }
  return 0;
}