void LstInsert(struct elem *neu, struct elem *last){
    struct elem *ptr;
    if(root==NULL){
        printf("Keine Elemente vorhanden!\n");
        return;
    } else {
    ptr=root;
    while(ptr!=NULL){
        ptr=ptr->next;
        if(ptr==NULL){
            ptr=last;
            last->next=neu;
            neu=malloc(sizeof(struct elem));
            neu->Messwert=ptr->Messwert;
            neu->next=NULL;

            }
        }
    }
}