can't under stand why the queue function program works at the first time but don't work like expected after that

this is my code

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#include <stdio.h>
#include <stdlib.h>

int Enqueue(int[],int,int*,int);
int Dequeue(int[],int,int*,int);
int show(int[],int*);

int main (void)
{
    int q[]={1,2,3,4,5,6,7,8,9,10};
    int n = sizeof(q)/sizeof(int);
    int numelem = n;
    int l=0;
    int e=0;
    int d=0;
    while(l!=4)
    {
        printf("°°°°menu items°°°°\n");
        printf("1-->enqueue\n");
        printf("2-->dequeue\n");
        printf("3-->show\n");
        printf("4-->exit\n");
        fflush (stdin);
        scanf("%d",&l);
        if(l==1)
        {
            printf("plz enter the element you want to add --> ");
            scanf("%d",&e);
            Enqueue(q,e,&numelem,n);
            //printf("Q");
        }    
        else if(l==2)
        {
            Dequeue(q,d,&numelem,n);
        }
        else if(l==3)
        {
            show(q,&numelem);
        }
        else if(l==4)
        {
            break;
        }
        else
        {
            printf("plz enter a number from the menu!!!!!\n");
        }
    }
    printf("bye bye\n");
}
int Enqueue(int q[],int e,int *numelem,int n)
{
    int inserted=0;
    n++;
    if(*numelem<n)
    {
        inserted=1;
        q[*numelem]=e;
        *numelem+=1;
    }

    return inserted;

}
int Dequeue(int q[],int d,int *numelem,int n)
{
    int deleted=0;
    if(*numelem==n)
    {
        deleted=1;
        d=q[0];
        *numelem-=1;
        n--;
    }
    for (int i=0;i<=n;i++)
    {
        q[i-1]=q[i];
    }
    printf("the deleted item is --> %d\n",d);
    return deleted;
}
int show(int q[],int *numelem)
{
    for (int i=0;i<*numelem;i++)
    {
        printf("%d,",q[i]);
    }
    printf("\n");
    return *numelem;
}

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there are no compiler error

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and when you enter Equeue of Dequeue for the first time it works

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but if you try again in the same time the result is unexpected

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I am a student who trying to do his homework so please don't be mean in the comments and thanks any way

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plz help me