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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:

;

}

}