WAP to reverse the order of the elements in the stack using additional Queue.

 #include<stdio.h> 

#include<stdlib.h> 

#define MAX_SIZE 100

struct Queue

{

  int items[MAX_SIZE];

  int front;

  int rear;

};

struct Stack

{

  int items[MAX_SIZE];

  int top;

};

void enqueue (struct Queue *q, int item)

{

  if (q->rear == MAX_SIZE - 1)

    {

      printf ("Queue overflow\n");

      return;

    }

  if (q->front == -1)

    {

      q->front = 0;

    }

  q->rear++;

  q->items[q->rear] = item;

}

int dequeue (struct Queue *q)

{

  if (q->front == -1)

    {

      printf ("Queue underflow\n");

      return -1;

    }

  int item = q->items[q->front];

  q->front++;

  if (q->front > q->rear)

    {

      q->front = q->rear = -1;

    }

  return item;

}

void display (struct Queue *q)

{

  if (q->rear == -1)

    {

      printf ("Queue is empty\n");

      return;

    }

  for (int i = q->front; i <= q->rear; i++)

    {

      printf ("%d ", q->items[i]);

    }

  printf ("\n");

}

void push (struct Stack *s, int item)

{

  if (s->top == MAX_SIZE - 1)

    {

      printf ("Stack overflow\n");

      return;

    }

  s->top++;

  s->items[s->top] = item;

}

int pop (struct Stack *s)

{

  if (s->top == -1)

    {

      printf ("Stack underflow\n");

      return -1;

    }

  int item = s->items[s->top];

  s->top--;

  return item;

}

int main ()

{

  struct Queue q;

  q.front = -1;

  q.rear = -1;

  struct Stack s;

  s.top = -1;

  enqueue (&q, 1);

  enqueue (&q, 2);

  enqueue (&q, 3);

  enqueue (&q, 4);

  printf ("Queue before reversing:\n");

  display (&q);

  while (q.front != -1)

    {

      push (&s, dequeue (&q));

    }

  while (s.top != -1)

    {

      enqueue (&q, pop (&s));

    }

  printf ("Queue after reversing:\n");

  display (&q);

  return 0;

}