hdu 1026 Ignatius and the Princess I(bfs+priority_queue)

第一次写这种题，参考一下网上的代码。

#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
int dir[][2] = {{-1,0}, {0,1}, {1,0}, {0,-1}};　　　　//四个方向
int n, m;
const int MAXN = 105;
struct Node
{
    int x, y, time;
    friend bool operator<(Node a, Node b)            //重载
    {
        return a.time > b.time;
    }
};
struct cmap
{
    char c;
    int nx, ny;
}map[MAXN][MAXN];
int fight[MAXN][MAXN], vis[MAXN][MAXN];              //fight用来标记有monster的HP
int bfs()
{
    Node now, next;
    std::priority_queue<Node> q;
    now.x = n - 1, now.y = m - 1;
    char s = map[now.x][now.y].c;
    if (s>='1' && s<= '9')
    {
        now.time = map[now.x][now.y].c - '0';
        fight[now.x][now.y] = map[now.x][now.y].c - '0';
    }
    else
        now.time = 0;
    q.push(now);
    while (!q.empty())
    {
        now = q.top();
        q.pop();
        if (now.x == 0 && now.y == 0)
            return now.time;
        for (int i = 0; i < 4; ++i)
        {
            next.x = now.x + dir[i][0];
            next.y = now.y + dir[i][1];
            if (next.x>=0 && next.x<n && next.y>=0 && next.y<m && 
                    map[next.x][next.y].c != 'X' && !vis[next.x][next.y])
            {
                vis[next.x][next.y] = 1;
                s = map[next.x][next.y].c;
                if (s>='1' && s<='9')
                {
                    next.time = now.time + s - '0' + 1;
                    fight[next.x][next.y] = s - '0';
                }
                else
                    next.time = now.time + 1;
                map[next.x][next.y].nx = now.x;
                map[next.x][next.y].ny = now.y;
                q.push(next);
            }
        }
    }
    return -1;
}
int main()
{
    while (scanf("%d %d", &n, &m) != EOF)
    {
        for (int i = 0; i < n; ++i)
            for (int j = 0; j < m; ++j)
                std::cin >> map[i][j].c;
        memset(vis, 0, sizeof(vis));
        memset(fight, 0, sizeof(fight));
        int ans = bfs();
        if (ans != -1)
        {
            printf("It takes %d seconds to reach the target position, let me show you the way.\n", ans);
            int num = 1, x = 0, y = 0;
            while (num <= ans)
            {
                int fx = map[x][y].nx, fy = map[x][y].ny;
                printf("%ds:(%d,%d)->(%d,%d)\n", num++, x, y, fx, fy);
                for (int t = 1; t <= fight[fx][fy]; ++t)
                    printf("%ds:FIGHT AT (%d,%d)\n", num++, fx, fy);
                x = fx, y = fy;
            }
        }
        else
            printf("God please help our poor hero.\n");
        printf("FINISH\n");
    }
    system("pause");
    return 0;
}