zoj 1649 Rescue

BFS..第一次使用C++ STL的队列来写广搜。

 

#include<stdio.h>

#include<string.h>

#include<math.h>

#include<queue>

#include<algorithm>

using namespace std;

const int maxn = 222;

struct Point{ int time, x, y; };

queue<Point> Q;

char mapp[maxn][maxn];

int mt[maxn][maxn];

int dir[4][2] = { { -1, 0 }, { 1, 0 }, { 0, -1 }, { 0, 1 } };

int main()

{

    int n, m, i, j, sx, sy, ex, ey, ans;

    while (~scanf("%d%d", &n, &m))

    {

        for (i = 0; i < n; i++) scanf("%s", mapp[i]);

        for (i = 0; i < n; i++)

        {

            for (j = 0; j < m; j++)

            {

                mt[i][j] = 0x7FFFFFFF;

                if (mapp[i][j] == 'a') sx = i, sy = j;

                if (mapp[i][j] == 'r') ex = i, ey = j;

            }

        }    

        Point ss; ss.time = 0; ss.x = sx; ss.y = sy;

        Q.push(ss);

        ans = 0x7FFFFFFF;

        while (!Q.empty())

        {

            Point h, t;

            h = Q.front(); Q.pop();

            if (h.x == ex&&h.y == ey&&h.time < ans) ans = h.time;

            for (i = 0; i < 4; i++)

            {

                int xx = h.x + dir[i][0], yy = h.y + dir[i][1];

                if (xx >= 0 && xx <= n-1&&yy >= 0 && yy <= m-1)

                {

                    if (mapp[xx][yy] != '#')

                    {

                        if (mapp[xx][yy] == 'x')

                        {

                            if (h.time + 2 < mt[xx][yy])

                            {

                                t.time = h.time + 2;

                                t.x = xx; t.y = yy;

                                mt[xx][yy] = h.time + 2;

                                Q.push(t);

                            }

                        }

                        else

                        {

                            if (h.time + 1 < mt[xx][yy])

                            {

                                t.time = h.time + 1;

                                t.x = xx; t.y = yy;

                                mt[xx][yy] = h.time + 1;

                                Q.push(t);

                            }

                        }

                    }

                }

            }

        }

        if (ans != 0x7FFFFFFF)printf("%d\n", ans);

        else printf("Poor ANGEL has to stay in the prison all his life.\n");

    }

    return 0;

}