pku 2049 Finding Nemo 第一周训练——搜索

http://poj.org/problem?id=2049

好纠结的一道题，刚拿过体来就已经懵了。这个图的信息到底该怎么存啊。。。纠结。看了别人的思路才A的。。

he,ve两个数组分别存放这平行于x轴，y轴的墙，门信息。。。

dis存储到达该点的最端距离。

View Code

#include <cstdio>
#include <cstring>
#include <queue>
#define maxn 250
#define inf 999999999
using namespace std;
struct node//优先队列的写法
{
    int x,y;
    int len;
    bool operator < (const node &a) const
    {
        return len > a.len;
    }
};
int n,m,sx,sy;
int dis[maxn][maxn],he[maxn][maxn],ve[maxn][maxn];
priority_queue<node>q;
int xmax,ymax;
void bfs()
{
    int x,y;
    for (x = 0; x <= xmax; ++x)
    {
        for (y = 0; y <= ymax; ++y)
        dis[x][y] = inf;
    }
    while (!q.empty()) q.pop();
    node pn;
    pn.x = 0; pn.y = 0; pn.len = 0;
    dis[0][0] = 0;
    q.push(pn);
    while (!q.empty())
    {
        pn = q.top();
        q.pop();
        x = pn.x; y = pn.y;
        if (x == sx && y == sy) return ;
        //向上走
        if (y + 1 <= ymax && dis[x][y + 1] > dis[x][y] + he[x][y + 1])
        {
            dis[x][y + 1] = dis[x][y] + he[x][y + 1];
            pn.x = x; pn.y = y + 1; pn.len = dis[x][y + 1];
            q.push(pn);
        }
        //向下走
        if (y - 1 >= 0 && dis[x][y - 1] > dis[x][y] + he[x][y])
        {
            dis[x][y - 1] = dis[x][y] + he[x][y];
            pn.x = x; pn.y = y - 1; pn.len = dis[x][y - 1];
            q.push(pn);
        }
        //向左走
        if (x - 1 >= 0 && dis[x - 1][y] > dis[x][y] + ve[x][y])
        {
            dis[x - 1][y] = dis[x][y] + ve[x][y];
            pn.x = x - 1; pn.y = y; pn.len = dis[x - 1][y];
            q.push(pn);
        }
        //向右走
        if (x + 1 <= xmax && dis[x + 1][y] > dis[x][y] + ve[x + 1][y])
        {
            dis[x + 1][y] = dis[x][y] + ve[x + 1][y];
            pn.x = x + 1; pn.y = y; pn.len = dis[x + 1][y];
            q.push(pn);
        }
    }
    dis[sx][sy] = -1;
}
int main()
{
    int x,y,d,t,i,j;
    double tx,ty;
    while (scanf("%d%d",&n,&m))
    {
        xmax = ymax = - 1;//记录最大x,与y
        memset(he,0,sizeof(he));
        memset(ve,0,sizeof(ve));
        if (n == -1 && m == -1) break;
        for (i = 0; i < n; ++i)
        {
            scanf("%d%d%d%d",&x,&y,&d,&t);
            if (d == 0)
            {
                for (j = 0; j < t; ++j)
                he[x + j][y] = inf;
                xmax = max(xmax,x + t);
                ymax = max(ymax,y);
            }
            else
            {
                for (j = 0; j < t; ++j)
                ve[x][y + j] = inf;
                xmax = max(xmax,x);
                ymax = max(ymax,y + t);
            }
        }
        for (i = 0; i < m; ++i)
        {
            scanf("%d%d%d",&x,&y,&d);
            if (d == 0)
            {
                he[x][y] = 1;
            }
            else
            {
                ve[x][y] = 1;
            }
        }
        scanf("%lf%lf",&tx,&ty);
        if (tx > xmax || ty > ymax)
        {
            puts("0");
        }
        else
        {
            sx = (int)tx;
            sy = (int)ty;
            bfs();
            printf("%d\n",dis[sx][sy]);
        }
    }
    return 0;
}