enqueue and deuque funct.

Hi all

I'm having kind of queue problem in my program while handling queues,,

basicly in my program I have 4 different quees , you can try to think like, there are 2 different cities
and 2 different airports, and 1 takeoff and 1 landing queues an..Totally I've got 4 different linked list...
Every take off queues consist of just 2 item, landing has got no limit...

User fill in the queues in the begining of program by enterin two item into every queue list.
like

A city Take Off--> x-y
A City Landing--> k-f

B city take off--> p-m
B city take off--> j-t

After user filled in by entering char names like above,

User enters a direction like A to B
and

Program Takes first element of A City's takeoff and transfers it into B city's landing,
like so

A to B

A city take off--> Y
A city Landing--> K F

B city take off--> P M
B city landing --> X - J- T

while doing this I'm using tradational enqueue and dequeue functions but I'm having a problem while
transfering A link's one element to B link...
here is the a part of the code

Code:

 

if(flight_choice=='I');{choice=1;}
if(flight_choice=='A');{choice=2;}
if(flight_choice=='E');{choice=3;}
switch(choice){
               case 1:
                    flight_choice2=getch();
                    flight_choice2=toupper(flight_choice2);
                    printf("%c\n",flight_choice2);
                    if(flight_choice2 == 'A'){
                                      dequeue(&ist_take_head,&key1);
                                      enqueue(&ank_land_head,key1);
                                      dequeue(&ist_land_head,&key1);
                                      enqueue(&ist_take_head,key1);
                                      }

void enqueue( flight** head, char key )
{
  flight* newNode = malloc(sizeof(flight));
  newNode->key = key;
  newNode->next = NULL;
  if ( *head == NULL ) 
  {
    *head = newNode; 
  }
  else
  {
    flight* last = *head;
    while ( last->next != NULL )
      last = last->next;
    last->next = newNode;
  }
}

void dequeue(flight** head, char *key) {
  if ( *head == NULL ) 
  {
    *key = 0;
  }
  else 
  {
    *key = (*head)->key;
    *head = (*head)->next;
  }
}

What I dont understand is what I have to pass as a key,while doing dequeue function the key(which is the name of element in the linked list),
I pass into that function.

I know it's not a clear explanation but I got totally confused so that I cant excatly explain my question .

Firstly, revise your if statements

Code:

if(flight_choice=='I');{choice=1;}
if(flight_choice=='A');{choice=2;}
if(flight_choice=='E');{choice=3;}

These in-fact do nothing (the trailing ; indicates end-of-statement), I think you mean

Code:

if(flight_choice=='I')
    choice=1;
if(flight_choice=='A')
    choice=2;
if(flight_choice=='E')
    choice=3;

And then again that can be clean'd up with the use of a switch

• Getch is also non-standard.
• There is no corisponding free() for your malloc() (this is in-fact a memory leak)
• ...

hocam bu data ödevi deil mi yaa ?

burda buna cevap çıkması cok zor bence

Originally Posted by ercumania

hocam bu data ödevi deil mi yaa ?

burda buna cevap çıkması cok zor bence

problem's been solved...thanx alot...

Cikti

ugrastirdi ama biraz

Originally Posted by m0ntana

problem's been solved...thanx alot...

Cikti

ugrastirdi ama biraz

çok az tiyo versen ?

Originally Posted by ercumania

çok az tiyo versen ?

sorry for the answer in another language rather than english..

Her şehir için 1 take-off 1 landing head pointer tanımlıyorsun, totalde 6 tane oluyor...

Her birini farklı bir linked list olarak düşün, ve kullanıcıdan her şehir için 2 takeoff 2 landing uçağı alıyorsun, yani her bir queue de 2 şer tane item olmuş oluyor.

Bunu hazır fonksyonlarla yapıyosun zaten

Code:

void enqueue( flight** head, char key )
{
  flight* newNode = malloc(sizeof(flight));
  newNode->key = key;
  newNode->next = NULL;
  if ( *head == NULL ) 
  {
    *head = newNode; 
  }
  else
  {
    flight* last = *head;
    while ( last->next != NULL )
      last = last->next;
    last->next = newNode;
  }
}

buda dequeue part ı

Code:

void dequeue(flight** head, char *key) {
  if ( *head == NULL ) 
  {
    *key = 0;
  }
  else 
  {
    *key = (*head)->key;
    *head = (*head)->next;
  }
}

aldığın her char ı enquee e yolla aynen o kuyruğa atıyo zaten,
asıl mesele ondan sonra zaten switch case le kullanıcıdan aldığı direction ı kontrol etmen lazım
I A- E I gibi onuda yukadaki gibi yaptım ben....