Algoritmi i strukture 2

#include <stdio.h>
#include <stdlib.h>
#define SIZE 10  /* Size of Stack */
int CQ[SIZE],f=-1,r=-1;       /* Global declarations */
int s[SIZE],top=-1;       /* Global declarations */

void push(int elem)
{                       /* Function for PUSH operation */
    if( Sfull()) printf("\n\n Overflow!!!!\n\n");
    else
    {
        ++top;
        s[top]=elem;
    }
}

int pop()
{                      /* Function for POP operation */
    int elem;
    if(Sempty()){ printf("\n\nUnderflow!!!!\n\n");
    return(-1); }
    else
    {
        elem=s[top];
        top--;
        return(elem);
    }
}

int Sfull()
{                     /* Function to Check Stack Full */
    if(top == SIZE-1) return 1;
    return 0;
}

int Sempty()
{                    /* Function to Check Stack Empty */
    if(top == -1) return 1;
    return 0;
}

void displayStek()
{                  /* Function to display status of Stack */
    int i;
    if(Sempty()) printf(" \n Empty Stack\n");
    else
    {
        for(i=0;i<=top;i++)
            printf("\n%d\n",s[i]);
        printf("^Top\n\n");
    }
}
void insert(int elem)
{                       /* Function for Insert operation */
    if( CQfull()) printf("\n\n Overflow!!!!\n\n");
    else
    {
        if(f==-1)f=0;
        r=(r+1) % SIZE;
        CQ[r]=elem;
    }
}
int Delete()
{                      /* Function for Delete operation */
    int elem;
    if(CQempty()){ printf("\n\nUnderflow!!!!\n\n");
    return(-1); }
    else
    {
        elem=CQ[f];
        if(f==r){ f=-1; r=-1;} /* Q has only one element ? */
        else
            f=(f+1) % SIZE;
        return(elem);
    }
}
int  CQfull()
{                     /* Function to Check Circular Queue Full */
/* proverava se pre povećanja r*/
    if( (f==r+1) || (f == 0 && r== SIZE-1)) return 1;
    return 0;
}

int CQempty()
{                    /* Function to Check Circular Queue Empty */
    if(f== -1) return 1;
    return 0;
}

void displayRed()
{        /* Function to display status of Circular Queue */
    int i;
    if(CQempty()) printf(" \n Empty Queue\n");
    else
    {
        printf("Front[%d]->",f);
        for(i=f;i!=r;i=(i+1)%SIZE)
            printf("%d ",CQ[i]);
        printf("%d ",CQ[i]);
        printf("<-[%d]Rear\n",r);
    }
}
void RedUmetanje()
{
    int i;
    insert(2018);
    for(i=2;i<=7;i++)
    {
        insert(2018*i);
    }
}
void StekUmetanje()
{
    int i;
    for(i=f;i!=r;i=(i+1)%SIZE)
        if(CQ[i]%5==0)
            push(CQ[i]);
}
int main()
{
    RedUmetanje();
    displayRed();
    StekUmetanje();
    displayStek();
    return 0;
}