DataType PQ_FindMin(PriorityQueue p_queue)
{
if(!PQ_IsEmpty(p_queue))
return p_queue->m_Array[1];
printf("ERRoR!! Queue is Empty!!");
return p_queue->m_Array[0];
}
int main()
{
PriorityQueue* PQ = PQ_Create(3);
PQNode Popped;
PQNode Nodes[7] =
{
{34, (void*)"코딩"},
{12, (void*)"고객미팅"},
{87, (void*)"커피타기"},
{45, (void*)"문서작성"},
{35, (void*)"디버깅"},
{66, (void*)"이닦기"}
};
PQ_Enqueue(PQ, Nodes[0]);
PQ_Enqueue(PQ, Nodes[1]);
PQ_Enqueue(PQ, Nodes[2]);
PQ_Enqueue(PQ, Nodes[3]);
PQ_Enqueue(PQ, Nodes[4]);
PQ_Enqueue(PQ, Nodes[5]);
printf("큐에 남아 있는 작업의 수 : %d\n", PQ->UsedSize);
while (!PQ_IsEmpty(PQ))
{
PQ_Dequeue(PQ, &Popped);
PrintNode(&Popped);
}
return 0;
}
DataType PQ_DeleteMin(PriorityQueue p_queue)
{
int i, child;
DataType minEle, lastEle;
if(PQ_IsEmpty(p_queue))
{
printf("ERROR!! Queue is Empty");
return p_queue->m_Array[0];
}
minEle = p_queue->m_Array[1];
lastEle = p_queue->m_Array[p_queue->m_Size--];
for(i=1; i*2 < p_queue->m_Size; i = child)
{
child = i*2;
// get the smaller child;
if (child != p_queue->m_Size && p_queue->m_Array[child+1] < p_queue->m_Array[child])
child++;
//percolate one level
if(lastEle > p_queue->m_Array[child])
p_queue->m_Array[i] = p_queue->m_Array[child];
else
break;
}
p_queue->m_Array[i] = lastEle;
return minEle;
}
void Dijkstra(Graph* G, Vertex* StartVertex, Graph* ShortestPath )
{
int i = 0;
PQNode StartNode = { 0, StartVertex };
PriorityQueue* PQ = PQ_Create(10);
Vertex* CurrentVertex = NULL;
Edge* CurrentEdge = NULL;
int* Weights = (int*) malloc( sizeof(int) * G->VertexCount );
Vertex** ShortestPathVertices =
(Vertex**) malloc( sizeof(Vertex*) * G->VertexCount );
Vertex** Fringes = (Vertex**) malloc( sizeof(Vertex*) * G->VertexCount );
Vertex** Precedences = (Vertex**) malloc( sizeof(Vertex*) * G->VertexCount );
CurrentVertex = G->Vertices;
while ( CurrentVertex != NULL )
{
Vertex* NewVertex = CreateVertex( CurrentVertex->Data );
AddVertex( ShortestPath, NewVertex);
Fringes[i] = NULL;
Precedences[i] = NULL;
ShortestPathVertices[i] = NewVertex;
Weights[i] = MAX_WEIGHT;
CurrentVertex = CurrentVertex->Next;
i++;
}
PQ_Enqueue ( PQ, StartNode );
Weights[StartVertex->Index] = 0;
while( ! PQ_IsEmpty( PQ ) )
{
PQNode Popped;
PQ_Dequeue(PQ, &Popped);
CurrentVertex = (Vertex*)Popped.Data;
Fringes[CurrentVertex->Index] = CurrentVertex;
CurrentEdge = CurrentVertex->AdjacencyList;
while ( CurrentEdge != NULL )
{
Vertex* TargetVertex = CurrentEdge->Target;
if ( Fringes[TargetVertex->Index] == NULL &&
Weights[CurrentVertex->Index] + CurrentEdge->Weight <
Weights[TargetVertex->Index] )
{
PQNode NewNode = { CurrentEdge->Weight, TargetVertex };
PQ_Enqueue ( PQ, NewNode );
Precedences[TargetVertex->Index] = CurrentEdge->From;
Weights[TargetVertex->Index] =
Weights[CurrentVertex->Index] + CurrentEdge->Weight;
}
CurrentEdge = CurrentEdge->Next;
}
}
for ( i=0; i<G->VertexCount; i++ )
{
int FromIndex, ToIndex;
if ( Precedences[i] == NULL )
continue;
FromIndex = Precedences[i]->Index;
ToIndex = i;
AddEdge( ShortestPathVertices[FromIndex],
CreateEdge(
ShortestPathVertices[FromIndex],
ShortestPathVertices[ToIndex],
Weights[i] ) );
}
free( Fringes );
free( Precedences );
free( ShortestPathVertices );
free( Weights );
PQ_Destroy( PQ );
}
