HDU 1181 变形课

HDU 1181 变形课

构图，BFS。
以下是我的代码：

#include < iostream >
#include < string >
#include < queue >
#include < cstdio >
#include < cstring >
using   namespace  std;
const   string  kEndSign ( " 0 " );
const   int  kBeginNum ( ' b ' - ' a ' + 1 ),kEndNum ( ' m ' - ' a ' + 1 );

int  main()
{
     /*
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
    // */
    
     string  s;
     bool  map[ 27 ][ 27 ] = { false };
     while (cin >> s)
    {
         if (s == kEndSign)
        {
             bool  visited[ 27 ] = { false },success( false );
            queue < int >  q;
            q.push(kBeginNum);
            visited[kBeginNum] = true ;
             while ( ! q.empty())
            {
                 int  now = q.front();q.pop();
                 if (now == kEndNum)
                {
                    success = true ;
                     break ;
                }
                 for ( int  i = 1 ;i <= 26 ;i ++ )
                     if ( ! visited[i]  &&  map[now][i])
                    {
                        q.push(i);
                        visited[i] = true ;
                    }
            }
             if (success)
                cout << " Yes. " << endl;
             else  cout << " No. " << endl;
            
            memset(map, false , 27 * 27 * sizeof ( bool ));
        }
         else
            map[s[ 0 ] - ' a ' + 1 ][s[s.size() - 1 ] - ' a ' + 1 ] = true ;
    }
    
return   0 ;
}