In article <1110040992.1e52c0a3ea5a271df954b0ac777f706d@teran ews>,
<ab*@cus.com> wrote:
:I'm trying to write a c application that calculates the average time it
:takes for someone in line at an ice cream stand to get an ice cream
:cone. But, I don't really know where to start. Does anyone have any
:source code for queues I could look at?
Basic queues are first year programming exercises -- and they
aren't what you need anyhow. Calculating wait times does not require
implimenting any queues -- not unless you want to "calculate" the
times by simulation instead of by statistics.
If what you need is simulation instead of calculation, then
you can use something like this:
/* Warning: bugs have been deliberately put into this code */
typedef struct fifoQ_struct fifoQ_s;
typedef fifoQ_s *fifoQ;
fifoQ Qhead = NULL;
fifiQ Qtail = NULL;
/* remember, there is are deliberate bugs lurking around here somewhere */
void fifoQ_push( fifoQ Qentry )
{
if (Qhead == NULL) {
Qhead = Qtail = Qentry
} else {
Qtail->next = Qentry
}
}
/* remember, there aare deliberate bugs lurking around here somewhere */
fifoQ fifoQ_pop(void)
{
if (Qhead) {
fifoQ Qentry = Qhead;
Qhead = Qhead->next;
return Qentry;
}
return Qtail;
}
If you need multiple lineups, you will need to make changes.
The above is not intended to be general multi-queue code -- and
because we are not here to write assignments for you, I have
deliberately introduced bugs into the code above: in debugging the
code, you will learn more about how queues work than if I were to just
give you correct code.
--
Studies show that the average reader ignores 106% of all statistics
they see in .signatures.
