Queue using array

#include<stdio.h>

int q[100];
int q_size=0, i = 0, max_stack_size = 10;

void print_stack()
{
    printf("current queue : ");
    for(i=0;i<q_size;i++)
    {
       printf("%d ",q[i]);
    }
    printf("\n");
}

void push(int number)
{
    printf("-->push(%d)\n",number);

    //do push
    if( q_size <= max_stack_size ){
        q[q_size] = number;
        q_size++;

        print_stack();
    } else{
        printf("Queue Overflow\n");
    }

}

int pop()
{
    printf("-->pop()\n");
    int num;

    //do pop
    if( q_size > 0 ){
       q_size--;
       for( i=0; i < q_size; i++ ){
         q[i] = q[i + 1];
       }
        print_stack();
    } else{
        printf("Queue Empty\n");
    }

    return num;
}


int main(){
    push(5);
    push(6);
    push(7);
    pop();
    push(4);
    pop();
    pop();

}