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

typedef struct list{
    int value;
    struct list* next;
} node;

node* reformat(node* first, int number, node* thisnode){
    while(number && thisnode->next){
        thisnode = thisnode->next;
        number--;
    }
    if(first != thisnode){
        node* last = thisnode;
        while(last->next){
            last = last->next;
        }
        node* prev = first;
        node* prev_of_prev = NULL;
        while(prev->next != thisnode){
            prev_of_prev = prev;
            prev = prev->next;
        }
        if(prev_of_prev){
            prev_of_prev->next = thisnode;
        }else{
            first = thisnode;
        }
        prev->next = NULL;
        last->next = prev;
        return reformat(first, number, thisnode);
    }else{
        return first;
    }
}

node* add_node(node* list, int value){
    node* prev = NULL;
    node* thisnode = list;
    while(thisnode){
        prev = thisnode;
        thisnode = thisnode->next;
    }
    node* new = malloc(sizeof(node));
    new->next = NULL;
    new->value = value;
    if(prev == NULL) return new;
    prev->next = new;
    return list;
}

void printlist(node* list){
    while(list){
        printf("%d ", list->value);
        list = list->next;
    }
    printf("\n");
}

int main(void) {
    node* list = NULL;
    for(int i = 0; i < 10; i++){
        list = add_node(list, i);
    }
    printlist(list);
    list = reformat(list, 5, list);
    printlist(list);
}