Procedure 6.13 (Insert Item In Queue)

Before seeing the solution make sure that you tried enough. Don’t paste the whole code, just find out the logic. If you stuck in trouble, just inform me on comment.

/**Bismillahir Rahmanir Rahim**/

#include <stdio.h>
int queue[20], front=0, rear, i, cndtn=0;
void q_insrt(int item)
{
    if(rear == 19)
    {
        printf("Overflow\n");
        cndtn = 1;
        return;
    }
    else
    {
        rear++;
        queue[rear] = item;
    }
}
int main()
{
    int n, item;
    printf("Please, input your QUEUE size (less then 20)\n");
    scanf("%d", &n);
    rear = n-1;
    printf("Insert %d item.\n", n);
    for(i=0; i<n; i++) scanf("%d", &queue[i]);
    while(1)
    {
        printf("Insert an Item.\n");
        scanf("%d", &item);
        q_insrt(item);
        if(cndtn == 1) return 0;
        for(i=front; i<=rear; i++)
            printf("%d  ", queue[i]);
        printf("\n");
    }
    return 0;
}