不知道

vi oldId = id( oldState );

int& oldDir = direction[oldId];

//--- Apply all applicable moves to it and handle the new state.

for( int move=0;move<18;move++ ){

if( applicableMoves[phase]& (1 << move) ){

//--- Apply the move.

vi newState= applyMove(move, oldState);

vi newId= id( newState );

int& newDir = direction[newId];

//--- Have we seen this state (id) from the other direction already?

//--- I.e. have we found a connection?

if( newDir && newDir != oldDir ){

//--- Make oldId represent the forwards and newId the backwards search state.

if( oldDir > 1 ){

swap( newId, oldId );

move =inverse( move);

}

//--- Reconstruct the connecting algorithm.

vi algorithm(1, move );

while(oldId != currentId){

algorithm.insert(algorithm.begin(),lastMove[ oldId] );

oldId =predecessor[ oldId];

}

while(newId != goalId){

algorithm.push_back(inverse( lastMove[newId ] ));

newId =predecessor[ newId];

}

//--- Print and apply the algorithm.

for( int i=0;i<(int)algorithm.size();i++ ){

cout <<"UDFBLR"[algorithm[i]/3]<< algorithm[i]%3+1;

currentState = applyMove( algorithm[i],currentState );

}

//--- Jump to the next phase.

goto nextPhasePlease;

}

//--- If we've never seen this state (id) before, visit it.

if( ! newDir ){

q.push(newState );

newDir =oldDir;

lastMove[newId ] = move;

predecessor[newId ] = oldId;

}

}

}

}

nextPhasePlease:

;

}

}