C Program to Reverse Elements in Queue

C Program to reverse elements in queue

#include<stdio.h>
#include<stdlib.h>
struct stackrecord
{
 int *array;
 int capacity;
 int tos;
};
 typedef struct stackrecord *stack;
 stack createstack(int max)
 {
  stack s;
  s=malloc(sizeof(struct stackrecord));
  if(s==NULL)
 {
 printf("out of space");
 }
  s->array=malloc((sizeof(int))*max);
  if(s->array==NULL)
 {
 printf("out of space");
 }
  s->capacity=max-1;
  s->tos=-1;
  return(s);
 }

int isemptys(stack s)
{
 return s->tos==-1;
}

int isfulls(stack s)
{
 return s->tos==s->capacity;
}

void push(int x,stack s)
{
 if(isfulls(s))
  printf("Overflow");
 else
 {
  printf("n %d is pushed",x);
  s->tos++;
  s->array[s->tos]=x;
 }
}

int topandpop(stack s)
{
 if(isemptys(s))
 {
  printf("n empty stack");
  return;
 }
 else
 {
  printf("n %d is popped",s->array[s->tos]);
  return s->array[s->tos--];
 }
}

struct queuerecord
{
 int *array;
 int front;
 int rear;
 int capacity;
};

typedef struct queuerecord *queue;

queue createqueue(int max)
{
  queue q;
  q=malloc(sizeof(struct queuerecord));
  if(q==NULL)
  printf("Error");
  q->array=malloc(sizeof(int)*max);
  if(q->array==NULL)
  printf("Error");
  q->capacity=max-1;
  q->front=-1;
  q->rear=-1;
  return q;
}

int isfullq(queue q)
{
 return (q->rear==q->capacity);
}

int isemptyq(queue q)
{
 return (q->front==-1);
}

void enqueue(queue q,int x)
{
 if(isfullq(q))
 printf("overflows");
 else
 {
  printf("n %d is enqueued",x);
  q->rear++;
  q->array[q->rear]=x;
  if(q->front==-1)
  q->front++;
 }
}

int frontanddelete(queue q)
{
 int p;
 if(isemptyq(q))
 {
  printf("underflow");
  return;
 }
 else
 {
  p=q->array[q->front];
  printf("n %d is front and deleted",p);
  q->front++;
  return p;
 }
}

void display(queue q)
{
 int i;
 if(isemptyq(q))
 {
  printf("underflow");
  return;
 }
 for(i=q->front;irear;i++)
  printf("%dt",q->array[i]);
}
 
int main()
{
 int max,ele,i,choice,n=0,y,z;
 queue q;
 stack s;
 printf("n Enter the maximum elements:");
 scanf("%d",&max);
 q=createqueue(max);
 s=createstack(max);
 while(1)
 {
  printf("n Menu:1.Insert 2.Display reversed order 3.exit");
  printf("n Enter the choice:");
  scanf("%d",&choice);
  switch(choice)
  {
   case 1:
   printf("n Enter the element:");
   scanf("%d",&ele);
   enqueue(q,ele);
   n++;
   break;
  
   case 2:
   printf("n Contents of the queue:");
   display(q);
   for(i=0;i< capacity;i++)
   {
    z=frontanddelete(q),s;
    push(z,s);
   }
  q->front=-1;
  q->rear=-1;
  for(i=0;i< capacity;i++)
  {
   y=topandpop(s);
   enqueue(q,y);
  }
  printf("n Reversed contents are:");
  display(q);
  break;
 
  case 3:
  exit(0);
  }
 }
}


Output