UESTC_棋盘游戏 CDOJ 578

  1 #include <iostream>
  2 #include <cstring>
  3 #include <cstdio>
  4 #include <algorithm>
  5 #include <cmath>
  6 #include <queue>
  7 
  8 
  9 using namespace std;
 10 
 11 const int Max= 6;
 12 int N,M,tid,ttx,tty;
 13 char G[Max][Max];
 14 bool vis[36][36][36][36];
 15 
 16 typedef struct status{
 17 int pos[4],step,pol,f;    
 18 friend bool operator < (status a,status b)
 19 {
 20   if (a.step + a.f < b.step + b.f) return false;
 21   if (a.step + a.f > b.step + b.f) return true;
 22   if (a.step < b.step) return false;
 23   else 
 24   return true;
 25 }
 26 };
 27 
 28 priority_queue<status>q;
 29 status start;
 30 int pol;
 31 int dir[4][2] = {0,1,0,-1,1,0,-1,0};
 32 
 33 /*A* */
 34 int caculatef(status& x){
 35 int result = 0;
 36 for(int i = 0;i<M;++i)
 37  result += (abs(x.pos[i] / N - ttx) + abs(x.pos[i] % N - tty) );
 38 return result;
 39 }
 40 
 41 
 42 bool judge(status &x){
 43 for(int i = x.pol;i < M;++i)
 44  for(int j = i;j < M;++j)
 45   if (i != j)
 46    {  
 47       int tx1 = x.pos[i] / N;
 48       int ty1 = x.pos[i] % N;
 49       int tx2 = x.pos[j] / N;
 50       int ty2 = x.pos[j] % N;
 51       if (tx1 == tx2 && abs(ty1 - ty2) == 1) return false;
 52       else if(ty1 == ty2 && abs(tx1-tx2) == 1) return false;
 53       else if(tx1 == tx2 && ty1 == ty2) return false;
 54    }
 55 return true;
 56 }
 57 
 58 
 59 int bfs(){
 60 memset(vis,false,sizeof(vis));
 61 vis[start.pos[0]][start.pos[1]][start.pos[2]][start.pos[3]] = true;
 62 start.step = 0;
 63 q.push(start);
 64 while(!q.empty())
 65 {
 66   status temp = q.top();q.pop();       
 67   if(temp.pos[temp.pol] == tid)
 68        temp.pol++;           
 69   if (temp.pol == M) return temp.step;
 70   for(int i = temp.pol;i<M;++i)
 71        for(int j = 0;j<4;++j)
 72          {
 73              int newx = temp.pos[i] / N + dir[j][0];
 74              int newy = temp.pos[i] % N + dir[j][1];
 75              if (newx >= N || newx < 0 || newy >= N || newy < 0) continue;
 76         int nid =  newx * N + newy;
 77         status nst = temp;
 78         nst.pos[i] = nid;
 79         if (!judge(nst)) continue;
 80         if (vis[nst.pos[0]][nst.pos[1]][nst.pos[2]][nst.pos[3]] ) continue;
 81         vis[nst.pos[0]][nst.pos[1]][nst.pos[2]][nst.pos[3]] = true;
 82         nst.step = temp.step + 1;
 83         nst.f = caculatef(nst);
 84         q.push(nst);
 85         }
 86 }
 87 
 88 return -1;
 89 }
 90 
 91 
 92 int main(int argc,char * argv[]){
 93 int T;
 94 scanf("%d",&T);
 95 while(T--)
 96 {
 97   while(!q.empty())
 98    q.pop();
 99   for(int i = 0;i<4;++i)
100    start.pos[i] = 0;
101   start.pol = 0;
102   scanf("%d%d%*c",&N,&M);
103   for(int i = 0;i<N;++i)    
104    gets(G[i]);
105   for(int i = 0;i<N;++i)
106    for(int j = 0;j<N;++j)
107     if(G[i][j] <= ‘4‘ && G[i][j] >=‘1‘)
108      start.pos[G[i][j] - ‘1‘] = i*N+j;
109     else if(G[i][j] == ‘x‘)
110      tid = i*N + j;
111   ttx = tid / N;
112   tty = tid % N;
113   start.f = caculatef(start);
114   cout << bfs() << endl;
115 }
116 return 0;    
117 }