queue_list.tar.gz

#include "queue_list.h" #include "fatal.h" typedef struct QNode { ElementType Element; struct QNode *Next; }QNode, *QNodePtr; struct Node { QNodePtr Front; QNodePtr Rear; }; int IsEmpty( Queue Q ) { return Q->Front == Q->Rear; } Queue CreateQueue( void ) { Queue Q; Q = malloc( sizeof( struct Node ) ); Q->Front = Q->Rear = malloc( sizeof( struct QNode ) ); if (!Q->Front) FatalError( "Out of space!!!"); Q->Front->Next = NULL; return Q; } void MakeEmpty( Queue Q ) { if( Q == NULL ) Error( "Must use CreateQueue first" ); else while( !IsEmpty( Q ) ) Dequeue( Q ); } void DisposeQueue( Queue Q ) { while( Q->Front ) { Q->Rear = Q->Front->Next; free( Q->Front ); Q->Front = Q->Rear; } printf( "\nDispose queue completed!!!" ); } void Enqueue( ElementType X, Queue Q ) { QNodePtr p; p = malloc( sizeof( QNode ) ); if (!p) FatalError( "Out of space!!!" ); p->Element = X; p->Next = NULL; Q->Rear->Next = p; Q->Rear = p; } ElementType Front( Queue Q ) { if ( !IsEmpty( Q ) ) return Q->Front->Next->Element; return 0; /* Return value used to avoid warning */ } void Dequeue( Queue Q ) { if ( !IsEmpty( Q ) ) { QNodePtr p; p = malloc( sizeof( QNode ) ); if (!p) FatalError( "Out of space!!!" ); p = Q->Front->Next; Q->Front->Next = p->Next; if ( Q->Rear == p ) Q->Rear = Q->Front; free( p ); } } ElementType FrontAndDequeue( Queue Q ) { if ( !IsEmpty( Q ) ) { QNodePtr p; p = malloc( sizeof( QNode ) ); if (!p) FatalError( "Out of space!!!" ); p = Q->Front->Next; ElementType temp = 0; temp = p->Element; Q->Front->Next = p->Next; if ( Q->Rear == p ) Q->Rear = Q->Front; free( p ); return temp; } Error( "Empty queue!!!" ); return 0; /* Return value used to avoid warning */ }