When define a maxQueue is 10, means it able to store 10 items in circular queue,but when I key in the 10 items, it show "Queue Full" in items number 10.
Where is the wrong in my code? Why it cannot store up to 10 items?
Output from my code:
Enter you choice: 1
Enter ID document to print : 21
Enter you choice: 1
Enter ID document to print : 22
Enter you choice: 1
Enter ID document to print : 23
Enter you choice: 1
Enter ID document to print : 24
Enter you choice: 1
Enter ID document to print : 25
Enter you choice: 1
Enter ID document to print : 26
Enter you choice: 1
Enter ID document to print : 27
Enter you choice: 1
Enter ID document to print : 28
Enter you choice: 1
Enter ID document to print : 29
Enter you choice: 1
Enter ID document to print : 30
Error: Queue Full
Here is my code:
CODE
#include <stdio.h>
#define maxQueue 10
typedef char BOOL;
typedef int itemType;
typedef struct QUEUE
{
int head;
int tail;
int items[maxQueue];
}queue;
void initQueue(queue *);
BOOL emptyQueue(queue *);
BOOL fullQueue(queue *);
void insertQueue(itemType ,queue *);
void deleteQueue(itemType *,queue *);
void menu();
void SendToPrint(queue *);
void Print(queue *);
int main()
{
queue nQ;
int i = 0;
//clrscr();
initQueue(&nQ);
do
{
menu();
scanf("%d",&i);
switch (i)
{
case 1:SendToPrint(&nQ);break;
case 2:Print(&nQ);break;
case 3:Exit(0);break;
default:printf("\nERROR");break;
}
}while (i!=3);
}
void SendToPrint(queue *q)
{
itemType nItem;
printf("\n\nEnter ID document to print :");
scanf("\t%d",&nItem);
insertQueue(nItem,q);
return;
}
void Print(queue *q)
{
int i;
BOOL state;
printf("\n\nCheck printer buffer...");
if(q->tail < q->head)
state = ((BOOL)(q->head - q->tail) > 4);
else
state = ((BOOL)(q->tail - q->head) > 4);
if (state)
{
for (i = 0;i<5;i++)
{
printf("\nID Document print %d",q->items[q->head]);
deleteQueue(q->items[q->head],q);
}
}
else
printf("\nError Printer buffer no enough\n");
return;
}
void menu()
{
printf("\n****Printer Spooling****\n");
printf("1 - Sent document to print\n");
printf("2 - Print document\n");
printf("3 - Exit\n");
printf("Please enter your choice :");
}
void initQueue(queue *q)
{
q->head = 0;
q->tail = 0;
}
BOOL emptyQueue(queue *q)
{
return ((BOOL)(q->head == q->tail));
}
BOOL fullQueue(queue *q)
{
return ((BOOL)(((q->tail+1) % maxQueue) == q->head));
}
void insertQueue(itemType nItem,queue *q)
{
if (fullQueue(q))
printf(" Error : Queue Full\n");
else
{
q->items[q->tail] = nItem;
q->tail = (q->tail+1)%maxQueue;
}
}
void deleteQueue(itemType *nItem,queue *q)
{
if (emptyQueue(q))
printf(" Error : Queue Empty\n");
else
{
q->head = (q->head + 1) % maxQueue;
}
}
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