list/joseph/loop_list.c

/*
 * @Author: your name
 * @Date: 2021-06-20 17:11:37
 * @LastEditTime: 2021-06-20 19:21:51
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: \slist\slist.c
 */
#include "loop_list.h"
#include "stdlib.h"
#include "stdio.h"


pkt_node_t pkt_creat_joseph(void)
{
    pkt_node_t p, r, h;

    p = (pkt_node_t)malloc(sizeof(struct pkt_node));
    p->next = p;
    p->data = 1;
    h = p;
    int n, i;
loop:
    printf("input a number:");
    scanf("%d", &n);

    if (n < 0)
    {
        printf("input error < 0\n");
        goto loop;
    }
    r = h;
    for (i = 2; i <= n; i++)
    {
        p = (pkt_node_t)malloc(sizeof(struct pkt_node));
        p->data = i;
        r->next = p;
        r = p; /* r ponit list tail */
    }
    p->next = h; /* tail node ponit head node */
    return h;
}

int pkt_show_list(pkt_node_t l)
{
    pkt_node_t p = l;
    int i = 0;
    while (p->next != l)
    {
        printf("l[%d] = %d\n", i, p->data);
        p = p->next;
        i++;
    }
    printf("l[%d] = %d\n", i, p->data);

    return 0;
}

int pkt_joseph(pkt_node_t l, int k, int m)
{
    PKT_ASSERT(l);
    pkt_node_t p = l;
    while (p->next->data != k)
    {
        p = p->next; /* find k node prev node*/
    }
    printf("l[k] = %d\n", p->next->data);

    pkt_node_t r = p;
    pkt_node_t q;
    int i;
    while (r->next != r)
    {
        for (i = 0; i < m - 1; i++) /* find next del node prev node */
        {
            r = r->next; 
        }
        q = r->next; /* save delete node to q */
        r->next = q->next;
        printf("del = %d\n", q->data);
        free(q); 
    }

    printf("del = %d\n", r->data); /* last node */
    free(r); 
    return 0;
}

int main(int argc, char **argv)
{
    pkt_node_t list;

    list = pkt_creat_joseph();
    pkt_show_list(list);   
    
    pkt_joseph(list, 3, 4);

    return 0;
}