nyoj 284 坦克大战 （优先队列）

题目链接：http://acm.nyist.net/JudgeOnline/status.php?pid=284

特殊数据：

5 5

BBEEY

EEERB

SSERB

SSERB

SSETB

7

非优先队列：

 #include<iostream>
 #include<cstdio>
 #include<algorithm>
 #include<cstring>
 #include<string>
 #include<cmath>
 #include<map>
 #include<queue>
 using namespace std;
 int e1,e2,m,n;
 int  mapp[][];
 int  vis[][];
 int dir[][]={-,,,,,,,-};
 int ans;
 struct T
 {
     int x,y;
 }now,eed;
 int bfs(int s1,int s2)
 {
     queue< T >aa;
     while(!aa.empty()) aa.pop();
     now.x=s1;now.y=s2;
     aa.push(now);
     while(!aa.empty())
     {
         eed=aa.front();
            aa.pop();
           if(eed.x==e1 && eed.y==e2)
               {
               if(ans>vis[eed.x][eed.y])
                   ans=vis[eed.x][eed.y];
                }
         for(int i=;i<;i++)
         {
           now.x=eed.x+dir[i][];now.y=eed.y+dir[i][];
             //cout<<now.x<<" "<<now.y<<" "<<endl;
             if( mapp[now.x][now.y]!= )
             {
                 if(vis[now.x][now.y]==)
                     { vis[now.x][now.y]=mapp[now.x][now.y]+vis[eed.x][eed.y]; aa.push(now); }
                   else if(mapp[now.x][now.y]+vis[eed.x][eed.y]<vis[now.x][now.y])
                    {
                       vis[now.x][now.y]= mapp[now.x][now.y]+vis[eed.x][eed.y] ;
                       aa.push(now);
                    }
             }
         }
     }
     return ans;
 //5 5
 //BBEEY
 //EEERB
 //SSERB
 //SSERB
 //SSETB
 }
 int main()
 {
     int i,j,k,t,s1,s2;
     char s;
     while(cin>>m>>n && m+n)
     {ans=;
         memset(mapp,,sizeof(mapp));
         memset(vis,,sizeof(vis));
         for(int i=;i<=m;i++)
            for(int j=;j<=n;j++)
             {
               cin>>s;
               if(s=='Y')
                  {s1=i;s2=j;}
               else if(s=='T')
                {e1=i;e2=j; mapp[i][j]=;}
                 else if(s=='B')
                    mapp[i][j]=;
                   else if(s=='E')
                      mapp[i][j]=;
                       else mapp[i][j]=;
             }
             int mm=bfs(s1,s2);
             if(mm<)
                 cout<<ans<<endl;
               else cout<<-<<endl;
     }
     return ;
 }
         

优先队列：

 #include<queue>
 #include<algorithm>
 #include<iostream>
 #include<cstdio>
 #include<cstring>
 using namespace std;
 char map[][];
 int  vis[][],m,n;
 int dir[][] = {,,-,,,-,,};
 int sx,sy,ex,ey;
 struct T
 {
     int x,y,step;

 }now,eed;
 bool operator<( T a, T b ){
     return a.step>b.step;
 }
 priority_queue<T>pp;
 bool judge(int x,int y)
 {
     if(x< || x>m || y< || y>n || vis[x][y]== || map[x][y]=='S' || map[x][y]=='R')
      return false;

      return true;
 }
 int bfs()
 {
     while(!pp.empty()) pp.pop();
     now.x = sx;  now.y = sy; now.step = ;
     vis[now.x][now.y]=;
     pp.push(now);
     while(!pp.empty())
     {
         eed = pp.top();
         pp.pop();
         // printf("%d %d \n",eed.x,eed.y);
         if(eed.x == ex && eed.y==ey)
             return  eed.step;

         for(int i=;i<;i++)
         {
             now.x = eed.x+dir[i][];
             now.y = eed.y+dir[i][];
             if(judge(now.x ,now.y))
             {
                 if(map[now.x][now.y] == 'B')
                     now.step = eed.step+;
                     else
                         now.step = eed.step+;
                 vis[now.x][now.y]= ;
                 pp.push(now);
             }
         }
     }
     return -;

 }
 int main()
 {
     while(scanf("%d %d",&m,&n) && m+n)
     {
         memset(vis,,sizeof(vis));
         for(int i =;i<=m;i++)
             for(int j =;j<=n; j++)
         {
             scanf(" %c",&map[i][j]);
             if(map[i][j] == 'Y')
             {
                 sx = i;sy = j;
             }
             if(map[i][j] == 'T')
             {
                 ex = i;ey = j;
             }
         }
              int ans = bfs();
              printf("%d\n",ans);
     }
     return ;
 }