【luogu P2385 青铜莲花池】 题解

题目链接：https://www.luogu.org/problemnew/show/P2385

莲花池什么的最漂亮啦！

最近刷了两天搜索= =我搜索一直是弱菜

直接套bfs

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring> 
using namespace std;
int n, m, m1, m2, sx, sy, ex, ey;
struct point{
    int x, y, t;
}q[4000001];
int ma[31][31];
int fx[9];
int fy[9];
void bfs()
{
    int tail = 2,head = 1; 
    q[head].x = sx, q[head].y = sy, q[head].t = 0;
    while(head!=tail)
    {     
        for(int i = 1; i <= 8; i++)
        {
            int nowx = q[head].x + fx[i];
            int nowy = q[head].y + fy[i];
            if(nowx == ex && nowy == ey)
            {
                printf("%d",q[head].t+1);
                return ;
            }
            if(nowx > m || nowx <= 0 || nowy > n || nowy <= 0 || ma[nowx][nowy] == 2 ) continue;
            ma[nowx][nowy] = 2;
            q[tail].x = nowx;
            q[tail].y = nowy;
            q[tail].t = q[head].t + 1;
            tail++;
        }    
        head++;
    }
    
}
int main()
{
    memset(ma,999,sizeof(ma));
    scanf("%d%d%d%d",&m,&n,&m1,&m2);
    for(int i = 1; i <= m; i++)
    for(int j = 1; j <= n; j++)
    {
        scanf("%d",&ma[i][j]);
        if(ma[i][j]==3)
        {
            sx = i;
            sy = j;
        }
        if(ma[i][j]==4)
        {
            ex = i;
            ey = j;
        }
        if(ma[i][j] == 0)
        {
            ma[i][j] = 2;    
        } 
    }
    fx[1] = m1, fx[2] = m1, fx[3] = 0-m1, fx[4] = 0-m1, fx[5] = m2, fx[6] = m2, fx[7] = 0-m2, fx[8] = 0-m2; 
    fy[1] = m2, fy[2] = 0-m2, fy[3] = m2, fy[4] = 0-m2, fy[5] = m1, fy[6] = 0-m1, fy[7] = m1, fy[8] = 0-m1;
    bfs();
    return 0;
}