Pushing values to a Stack from a Queue - c

Question

I am trying to push values in to a stack using a queue, but the thing is am not getting any pop from the stack( No output).
Here is what i have done :
#include<stdio.h>
#include<malloc.h>
#include<conio.h>
#define MAX 180
#define TRUE 1
#define FALSE 0
struct cakes {
int spongecake;
int meringue;
int chocalate;
int red_velvet;
struct cakes *next;
};
struct stack{
int top;
int cake[10];
};
struct Queue{
int front;
int rear;
int count;
int cake[10];
};
void conveyer_order(struct cakes *);
void baking_order(struct cakes *);
int isFull(struct stack *);
int isEmpty(struct stack *);
void push(struct stack *,int);
int pop(struct stack *);
void init(struct Queue *);
int isqueueFull(struct Queue*);
void insert(struct Queue*,int);
int isqueueEmpty(struct Queue *);
int removes(struct Queue *);
main()
{
struct cakes *head;
head=(struct cakes *)malloc(sizeof(struct cakes));
conveyer_order(head);
head->next=(struct cakes *)malloc(sizeof(struct cakes));
baking_order(head->next);
}
int isFull(struct stack *k)
{
if(k->top==10-1)
{
return TRUE;
}
else
{
return FALSE;
}
}
int isEmpty(struct stack *k)
{
if(k->top==-1)
{
return TRUE;
}
else
{
return FALSE;
}
}
int pop(struct stack *sptr)
{
int ret=NULL;
if(!isEmpty(sptr))
{
ret=sptr->cake[sptr->top];
sptr->top--;
return ret;
}
}
void push(struct stack *sptr,int x)
{
if(!isFull(sptr))
{
sptr->top++;
sptr->cake[sptr->top]=x;
}
}
void init(struct Queue *q)
{
q->front=0;
q->rear=10-1;
q->count=0;
}
int isqueueFull(struct Queue *q)
{
if(q->count==10)
{
return 1;
}
else
{
return 0;
}
}
void insert(struct Queue *q,int x)
{
if(!isqueueFull(q))
{
q->rear=(q->rear+1)%10;
q->cake[q->rear]=x;
q->count++;
}
}
int isqueueEmpty(struct Queue *q)
{
if(q->count==0)
{
return 1;
}
else
{
return 0;
}
}
int removes(struct Queue *q)
{
int cakeempty=NULL;
if(!isqueueEmpty(q))
{
cakeempty=q->cake[q->front];
q->front=(q->front+1)%10;
q->count--;
return cakeempty;
}
}
void baking_order(struct cakes *theorder)
{
int v=0;
struct stack baking;
struct Queue belt;
baking.top=-1;
int value1=0;
int value2=0;
theorder->spongecake=20;
theorder->chocalate=40;
theorder->red_velvet=30;
theorder->meringue=75;
init(&belt);
while(!isqueueFull(&belt))
{
insert(&belt,theorder->meringue);
insert(&belt,theorder->chocalate);
insert(&belt,theorder->red_velvet);
insert(&belt,(theorder->spongecake));
}
value1=removes(&belt);
while(!isqueueEmpty(&belt))
{
while(!isFull(&baking))
{
value2=removes(&belt);
if(value1>=value2)
{
push(&baking,value2);
value1=value2;
}
else
{
insert(&belt,value2);
}
}
}
while(!isEmpty(&baking))
{
printf("\n%d",pop(&baking));
}
}
I tried printing the values without passing in to the stack and it works , i think the problem is with the 2 while loops.
How can i fix this error ?
Thank you for your time.

Answer 1

The problem is you only ever push 4 items onto the stack, so the stack is never full and your while(!isFull(&baking)) becomes an infinite loop.
Let's see if I can explain why:
Before you start the while loop, value1 is 75.
Then you read value2 as 40.
Check if(value1>=value2)? Yes, so you push 40 and set value1 to 40.
Then restart the loop, read value2 as 30.
Check if(value1>=value2)? Yes, so you push 30 and set value1 to 30.
Then restart the loop, read value2 as 20.
Check if(value1>=value2)? Yes, so you push 20 and set value1 to 20.
Then restart the loop, read value2 as 75.
Check if(value1>=value2)? No, so you put 75 back in the queue.
Then restart the loop, read value2 as 40.
Check if(value1>=value2)? No, so you put 40 back in the queue.
Then restart the loop, read value2 as 30.
Check if(value1>=value2)? No, so you put 30 back in the queue.
Then restart the loop, read value2 as 20.
Check if(value1>=value2)? Yes, so you push 20 and set value1 to 20.
At this point, you have pushed 40, 30, 20, 20.
However, everything left in the queue is either 30, 40 or 75 and if(value1>=value2) will never evaluate to true again.
Therefore your stack is never filled, and you never get out of the while loop.