BFS+模拟 ZOJ 3865 Superbot

题目传送门

 /*
     BFS+模拟：dp[i][j][p] 表示走到i，j，方向为p的步数为多少；
             BFS分4种情况入队，最后在终点4个方向寻找最小值:)
 */
 #include <cstdio>
 #include <iostream>
 #include <algorithm>
 #include <cstring>
 #include <string>
 #include <queue>
 using namespace std;

 const int MAXN = 1e2 + ;
 const int INF = 0x3f3f3f3f;
 int dir[][][] = {
 {{, -}, {, }, {-, }, {, }},
 {{, }, {, -}, {, }, {-, }},
 {{-, }, {, }, {, -}, {, }},
 {{, }, {-, }, {, }, {, -}}
 };
 int dp[][][];
 int dp2[][][];
 int ans[][][];
 char maze[][];
 int sx, sy, ex, ey;
 int n, m, P;

 bool ok(int nx, int ny, int np)
 {
     if (nx <  || nx >= n || ny <  || ny >= m)   return false;
     if (maze[nx][ny] == '*' || dp[nx][ny][np] != -)   return false;

     return true;
 }

 void BFS(void)
 {
     int x, y, nx, ny, p, np;
     queue<int> q;
     q.push (sx);    q.push (sy);    q.push ();

     while (!q.empty ())
     {
         x = q.front (); q.pop ();
         y = q.front (); q.pop ();
         p = q.front (); q.pop ();

         if (x == ex && y == ey && ans[x][y][p] == -)
             ans[x][y][p] = dp[x][y][p];

         nx = x + dir[dp[x][y][p]/P%][p][];
         ny = y + dir[dp[x][y][p]/P%][p][];
         if (ok (nx, ny, p))     //move robot, not move dir
         {
             dp[nx][ny][p] = dp[x][y][p] + ;
             q.push (nx);    q.push (ny);    q.push (p);
         }

         np = p + ;
         if (np > )    np = ;
         if (ok (x, y, np))        //not move robot, move dir to right
         {
             dp[x][y][np] = dp[x][y][p] + ;
             q.push (x);    q.push (y);    q.push (np);
         }

         np = p - ;
         if (np < ) np = ;
         if (ok (x, y, np))        //not move robot, move dir to left
         {
             dp[x][y][np] = dp[x][y][p] + ;
             q.push (x);    q.push (y);    q.push (np);
         }

         if (dp[x][y][p] <= )        //not move
         {
             dp[x][y][p]++;
             q.push (x); q.push (y); q.push (p);
         }
     }

     return ;
 }

 int main(void)        //ZOJ 3865 Superbot
 {
     //freopen ("F.in", "r", stdin);

     int t;
     scanf ("%d", &t);
     while (t--)
     {
         memset (dp, -, sizeof (dp));
         memset (ans, -, sizeof (ans));

         scanf ("%d%d%d", &n, &m, &P);

         for (int i=; i<n; ++i) scanf ("%s", &maze[i]);
         for (int i=; i<n; ++i)
         {
             for (int j=; j<m; ++j)
             {
                 if (maze[i][j] == '@')  sx = i, sy = j;
                 else if (maze[i][j] == '$') ex = i, ey = j;
             }
         }

         dp[sx][sy][] = ;
         BFS ();

         int mn = INF;
         for (int i=; i<; ++i)
         {
             if (ans[ex][ey][i] == -)    continue;
             mn = min (mn, ans[ex][ey][i]);
         }

         if (mn == INF)  printf ("YouBadbad\n");
         else    printf ("%d\n", mn);
     }

     return ;
 }