HDOJ 1026 Ignatius and the Princess I（BFS+优先队列）

距离我问小龙这个题怎么写，时间已经过了半年( ╯□╰ )。。

两种路径输出，递归和非递归。会写两个是因为之前忘记清空队列，结果爆栈，以为是函数递归所致，所以又写了一个非递归的。

#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;

const int maxn = 1000;
const int dir[4][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
typedef struct Node
{
        int x, y, step;
        Node(int _x = 0, int _y = 0, int _step = 0):
                x(_x), y(_y), step(_step) {}
        bool operator <(const Node argu) const
        {
                return argu.step < step;
        }
        void out()
        {
                printf("%d %d %d\n", x, y, step);
        }
}nn;

struct Ship
{
        int fx, fy, sx, sy;
        Ship(int _fx = -1, int _fy = -1, int _sx = -1, int _sy = -1):
                fx(_fx), fy(_fy), sx(_sx), sy(_sy) {};
}ss[maxn][maxn];

priority_queue q;
int n, m;
char map[maxn][maxn];
bool vis[maxn][maxn];

bool check(nn p)
{
        if(vis[p.x][p.y])
                return false;
        if(p.x >= n || p.x < 0 || p.y >= m || p.y < 0)
                return false;
        if(map[p.x][p.y] == 'X')
                return false;
        return true;
}

int out(int x, int y)
{
        int hp = 0, fs;
        if(map[x][y] >= '1' && map[x][y] <= '9')
                hp = map[x][y] - '0';
        if(ss[x][y].fx == -1 && ss[x][y].fy == -1)
        {
                if(hp)
                        for(int i = 1; i <= hp; i++)
                                printf("%ds:FIGHT AT (%d,%d)\n", i, x, y);
                return hp + 1;
        }
        fs = out(ss[x][y].fx, ss[x][y].fy);
        printf("%ds:(%d,%d)->(%d,%d)\n", fs, ss[x][y].fx, ss[x][y].fy, x, y);
        if(hp)
                for(int i = 1; i <= hp; i++)
                        printf("%ds:FIGHT AT (%d,%d)\n", fs + i, x, y);
        return fs + hp + 1;
}

//void out(int x, int y)
//{
//        int ex = x, ey = y, tx, ty;
//        while(ss[ex][ey].fx != -1 && ss[ex][ey].fy != -1)
//        {
//                tx = ss[ex][ey].fx, ty = ss[ex][ey].fy;
//                ss[tx][ty].sx = ex, ss[tx][ty].sy = ey;
//                ex = tx, ey = ty;
//        }
//        int cnt = 0, hp;
//        while(ss[ex][ey].sx != -1 && ss[ex][ey].sy != -1)
//        {
//                hp = 0;
//                if(map[ex][ey] >= '1' && map[ex][ey] <= '9')
//                        hp = map[ex][ey] - '0';
//                while(hp--)
//                {
//                        printf("%ds:FIGHT AT (%d,%d)\n", ++cnt, ex, ey);
//                }
//                printf("%ds:(%d,%d)->(%d,%d)\n", ++cnt, ex, ey, ss[ex][ey].sx, ss[ex][ey].sy);
//                tx = ss[ex][ey].sx, ty = ss[ex][ey].sy;
//                ex = tx, ey = ty;
//        }
//        if(map[ex][ey] >= '1' && map[ex][ey] <= '9')
//        {
//                hp = map[ex][ey] - '0';
//                while(hp--)
//                {
//                        printf("%ds:FIGHT AT (%d,%d)\n", ++cnt, ex, ey);
//                }
//        }
//}

bool bfs()
{
        nn s;
        if(map[0][0] >= '1' && map[0][0] <= '9')
                s.step += map[0][0] - '0';
        q.push(s);
        vis[0][0] = true;

        while(!q.empty())
        {
                nn now = q.top();
                q.pop();
                if(now .x == n - 1 && now.y == m - 1)
                {
                        printf("It takes %d seconds to reach the target position, let me show you the way.\n", now.step);
                        out(now.x, now.y);
                        return false;
                }
                nn next;
                for(int i = 0; i < 4; i++)
                {
                        next.x = now.x + dir[i][0];
                        next.y = now.y + dir[i][1];
                        if(check(next))
                        {
                                next.step = now.step + 1;
                                if(map[next.x][next.y] >= '1' && map[next.x][next.y] <= '9')
                                        next.step += map[next.x][next.y] - '0';
                                q.push(next);
                                vis[next.x][next.y] = true;
                                ss[next.x][next.y].fx = now.x;
                                ss[next.x][next.y].fy = now.y;
                        }
                }
        }
        return true;
}

int main()
{
//        freopen("1026.in", "r", stdin);

        while(~scanf("%d%d", &n, &m))
        {
                while(!q.empty())
                        q.pop();
                for(int i = 0; i < n; i++)
                        scanf("%s", map[i]);
                memset(vis, false, sizeof(vis));
                memset(ss, -1, sizeof(ss));
                if(bfs())
                        printf("God please help our poor hero.\n");
                printf("FINISH\n");
        }
        return 0;
}