【HDOJ】2425 Hiking Trip

优先级队列+BFS。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;

#define MAXN 25

typedef struct node_st {
    int x, y, t;
    node_st() {}
    node_st(int xx, int yy, int tt) {
        x = xx; y = yy; t = tt;
    }
    friend bool operator < (node_st a, node_st b) {
        return a.t > b.t;
    }
} node_st;

char map[MAXN][MAXN];
int visit[MAXN][MAXN];
int dir[4][2] = {-1,0,1,0,0,-1,0,1};
int n, m, vp, vs, vt;
int sx, sy, ex, ey;

bool outRange(int x, int y) {
    if (x<0 || x>=n || y<0 || y>=m)
        return true;
    return false;
}

int bfs() {
    int i, x, y, t;
    priority_queue<node_st> que;
    node_st node;

    if (map[ex][ey] == '@')
        return -1;

    memset(visit, 0, sizeof(visit));
    map[sx][sy] = '@';
    que.push(node_st(sx, sy, 0));

    while (!que.empty()) {
        node = que.top();
        if (node.x==ex && node.y==ey)
            return node.t;
        que.pop();
        for (i=0; i<4; ++i) {
            x = node.x + dir[i][0];
            y = node.y + dir[i][1];
            if (outRange(x, y) || map[x][y]=='@')
                continue;
            if (map[x][y] == 'T')
                t = node.t + vt;
            if (map[x][y] == '.')
                t = node.t + vs;
            if (map[x][y] == '#')
                t = node.t + vp;
            if (visit[x][y]==0 || visit[x][y]>t) {
                que.push(node_st(x, y, t));
                visit[x][y] = t;
            }
        }
    }

    return -1;
}

int main() {
    int i, t=0;

    while (scanf("%d %d", &n, &m) != EOF) {
        scanf("%d%d%d", &vp, &vs, &vt);
        for (i=0; i<n; ++i)
            scanf("%s", map[i]);
        scanf("%d%d%d%d", &sx, &sy, &ex, &ey);
        i = bfs();
        printf("Case %d: %d
", ++t, i);
    }

    return 0;
}