ElementType pqDeleteMin( PriorityQueue H )
{
int i, Child;
ElementType MinElement, LastElement;
if( pqIsEmpty( H ) )
{
fprintf(stderr, "Priority queue is empty\n" );
return H->Elements[ 0 ];
}
MinElement = H->Elements[ 1 ];
LastElement = H->Elements[ H->Size-- ];
for( i = 1; i * 2 <= H->Size; i = Child )
{
/* Find smaller child */
Child = i * 2;
if(Child != H->Size && H->compareElementType(&(H->Elements[ Child + 1 ]),&(H->Elements[ Child ])) < 0)
Child++;
/* Percolate one level */
if(H->compareElementType(&(LastElement),&(H->Elements[ Child ])) > 0 )
H->Elements[ i ] = H->Elements[ Child ];
else
break;
}
H->Elements[ i ] = LastElement;
return MinElement;
}
void pqInsert( ElementType X, PriorityQueue H )
{
int i;
if( pqIsFull( H ) )
{
fprintf(stderr, "Priority queue is full\n" );
return;
}
for( i = ++H->Size; H->compareElementType(&(H->Elements[ i / 2 ]),&(X)) > 0; i /= 2 )
H->Elements[ i ] = H->Elements[ i / 2 ];
H->Elements[ i ] = X;
}
/*Added by J.Callut*/
void pqInsertIfSpaceOrGreaterThanMin(ElementType X, PriorityQueue H){
ElementType min;
if( ! pqIsFull( H ) )
pqInsert( X, H );
else{
min = pqFindMin(H);
if(H->compareElementType(&(X),&(min)) > 0){
pqDeleteMin(H);
pqInsert( X, H );
}
}
}
