Stack using queue code with output

Code

#include<stdio.h>

typedef struct
{
    int front,rear,arr[30];
}queue;

typedef struct
{
    queue q;
}stack;

stack s;

void init()
{
       s.q.front = s.q.rear = -1;
}

int isEmpty()
{
       if(s.q.front==-1)
            return 1;
       return 0;
}

void enqueue(int element)
{
        if(isEmpty())
             s.q.front++;
        s.q.arr[++s.q.rear] = element;
}

int dequeue()
{
        int element = s.q.arr[s.q.front];

        if(s.q.front==s.q.rear)                       //last element present
            init();
        else
            s.q.front++;

        return element;
}

int empty()
{
        if(isEmpty())
              return 1;
        return 0;
}


void push(int element)
{
         int i,j;

         enqueue(element);

         if(!empty())
         { 
              j=s.q.rear;

              for(i=s.q.front;i<j;i++)
              {
                   dequeue(s.q.arr[i]);
                   enqueue(s.q.arr[i]);
              }
         }
}

int pop()
{
          if(empty())
          {
                printf("\nStack is empty.Can't pop");
                return -1;
          }
          else
                return dequeue();
}


void display()
{
         int i;

         if(empty())
              printf("\nStack is empty");
         else
         {
              printf("\n");

              for(i=s.q.front;i<=s.q.rear;i++)
                      printf("%d  ",s.q.arr[i]);
         }
}


int main()
{
         int element;

         init();

         push(1);
         display();

         push(2);
         display();

         push(3);
         display();

         element = pop();
         if(element!=-1)printf("\nPopped element = %d",element);
         display();

         return 0;
}  

O/P

1
2  1
3  2  1
2  1