洛谷P1443 馬的遍歷 簡單BFS

洛谷P1443 傳送門

這題比較水，主要是要學一下優先隊列和結構體一起使用的方法還有重載結構體的優先級

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水題，初始化地圖爲-1，然後八個方向的bfs搜索即可

代碼如下：

#include <stdio.h>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <queue>
#include <deque>
#include <cstring>
#include <iterator>
#include <set>
#include <map>
#define ll long long
using namespace std;
int mp[405][405];
int vis[405][405];
int mov[8][2] = {-2, -1, 2, 1, 2, -1, -2, 1, 1, 2, -1, -2, 1, -2, -1, 2};
int n, m, sx, sy;

struct horse
{
    int x, y, step;
} a, b;
queue<horse> q;
void bfs()
{
    while (!q.empty())
    {
        a = q.front();
        q.pop();
        mp[a.x][a.y] = a.step;
        for (int i = 0; i < 8; i++)
        {
            int xx = a.x + mov[i][0];
            int yy = a.y + mov[i][1];
            if (xx < 1 || yy < 1 || xx > n || yy > m || vis[xx][yy])
                continue;
            vis[xx][yy] = 1;
            b.x = xx;
            b.y = yy;
            b.step = a.step + 1;
            q.push(b);
        }
    }
}
int main()
{
    cin >> n >> m >> sx >> sy;
    memset(mp, -1, sizeof(mp));
    a.x = sx;
    a.y = sy;
    a.step = 0;
    q.push(a);
    vis[sx][sy] = 1;
    bfs();
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= m; j++)
            printf("%-5d", mp[i][j]);
        cout << endl;
    }
    return 0;
}