queue_array.tar.gz

#include "queue_array.h" #include "fatal.h" /* Place in implementation file * Queue implementation is a dynamically allocated array*/ #define MinQueueSize ( 5 ) struct QueueRecord { int Capacity; int Front; int Rear; int Size; ElementType *Array; }; int IsEmpty( Queue Q ) { return Q->Size == 0; } void MakeEmpty( Queue Q ) { Q->Size = 0; Q->Front = 1; Q->Rear = 0; } static int Succ( int value, Queue Q ) { if ( ++value == Q->Capacity ) value = 0; return value; } void Enqueue( ElementType X, Queue Q ) { if( IsFull( Q ) ) Error( "Full queue" ); else { Q->Size++; Q->Rear = Succ( Q->Rear, Q ); Q->Array[ Q-> Rear ] = X; } } void Dequeue( Queue Q ) { if ( IsEmpty( Q ) ) Error( "Empty queue" ); else { Q->Size--; Q->Front++; } } ElementType FrontAndDequeue( Queue Q ) { ElementType temp = 0; if ( IsEmpty( Q ) ) Error( "Empty queue" ); else { Q->Size--; temp= Q->Array[ Q->Front ]; Q->Front = Succ( Q->Front, Q ); } return temp; } ElementType Front( Queue Q ) { if ( !IsEmpty( Q ) ) return Q->Array[ Q->Front ]; Error( "Empty queue" ); return 0; /* Return value used to avoid warning */ } int IsFull( Queue Q ) { return Q->Size == Q->Capacity; } Queue CreateQueue(int MaxElements ) { Queue Q; if ( MaxElements < MinQueueSize ) Error( "Queue size is too small!!!" ); Q = malloc( sizeof( struct QueueRecord ) ); if ( Q == NULL ) FatalError( "Out of space!!!" ); Q->Array = malloc( sizeof( ElementType ) * MaxElements ); if ( Q->Array == NULL ) FatalError( "Out of Space!!!" ); Q->Capacity = MaxElements; MakeEmpty( Q ); return Q; } void DisposeQueue( Queue Q ) { if ( Q != NULL ) { free( Q->Array ); free( Q ); } }