[C로 배우는 알고리즘] Circular Linked List

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

typedef struct _node
{
    int key;
    struct _node *next;
}node;

node *head;

void insert_nodes(int);
void delete_after(node*);
void josephus(int, int);

void main(void)
{
    int n, m;
    printf("\nIf you want to quit, enter 0 of minus value");

    while(1)
    {
        printf("\nEnter N and M -> ");
        scanf("%d %d", &n, &m);

        if(n <= 0 || m <= 0)
            return;
        josephus(n, m);
    }
}

void insert_nodes(int k)
{
    node* t;
    int i;

    t = (node*)malloc(sizeof(node));
    t->key = 1;
    head = t;

    for(i=2;i<=k;++i)
    {
        t->next = (node*)malloc(sizeof(node));
        t = t->next;
        t->key = i;
    }
    t->next = head;
}

void delete_after(node* t)
{
    node* s;
    s = t->next;
    t->next = t->next->next;
    free(s);
}

void josephus(int n, int m)
{
    node* t;
    int i;
    insert_nodes(n);
    t = head;
    printf("\nAnswer : ");
    while(t != t->next)
    {
        for(i=0; i<m-1; ++i)
            t = t->next;

        printf("%d ", t->next->key);
        delete_after(t);
    }
    printf("%d", t->key);
}