1. 使用单项循环链表解决约瑟夫问题：
#include <stdio.h>
#include <stdlib.h>
typedef struct looplist{
int date;
struct looplist *next;
}looplist;
//创建循环链表
looplist * looplist_creat(){
looplist *head = NULL;
head = (looplist*)malloc(sizeof(looplist));
head->date = 1;
head->next = head;
return head;
}
//插入节点
void looplist_insert(looplist* head,int value){
looplist *temp = NULL;
temp = (looplist*)malloc(sizeof(looplist));
temp->date = value;
temp->next = head->next;
head->next = temp;
}
//遍历1
void looplist_show(looplist *head){
looplist* p = NULL;
p = head;
do{
printf("%d ",p->date);
p = p->next;
}while(p != head);
puts("");
}
void looplist_del(looplist* head,looplist* headpre,looplist* headtemp){
printf("%d ",headtemp->date);
looplist *p =NULL;
p = headtemp;
headpre->next = headtemp->next;
printf("\n");
free(p);
p=NULL;
}
looplist * joseph_creat(int person){
int i;
looplist * joseph = NULL;
joseph = looplist_creat();
for(i = person;i >= 2;i--){
looplist_insert(joseph,i);
}
return joseph;
}
void joseph(int person,int start,int num){
looplist * head = NULL;
looplist * headpre = NULL;
head = joseph_creat(person);
looplist_show(head);
looplist* headtemp = head;
while(headtemp->next != head){
headtemp = headtemp->next;
}
headpre = headtemp;
headtemp = head;
while(headtemp->date != start){
headpre = headtemp;
headtemp = headtemp->next;
}//未判断start在链表内，死循环风险
while(headtemp!=headtemp->next){
int counttemp = 1;
while(counttemp != num){
headpre = headtemp;
headtemp = headtemp->next;
counttemp++;
}
looplist_del(head,headpre,headtemp);
headtemp = headtemp->next;
}
printf("%d\n",headtemp->date);
free(headtemp);
headtemp = NULL;
head = NULL;
}
int main(int argc, const char *argv[])
{
joseph(8,3,4);//8人，从第3个人开始数，数4个数出列
return 0;
}
2. 双向循环链表
#include <stdio.h>
#include <stdlib.h>
typedef struct node{
int date;
struct node * priv;
struct node * next;
}doublelist;
doublelist * doublelist_creat(){
doublelist * head = NULL;
head = (doublelist*)malloc(sizeof(doublelist));
head->priv = head;
head->next = head;
return head;
}
void doublelist_head_insert(doublelist * head,int value){
doublelist * temp = doublelist_creat();
temp->date = value;
temp->next = head->next;
head->next->priv = temp;
temp->priv = head;
head->next = temp;
}
void doublelist_show(doublelist * head){
doublelist * temp = head->next;
while(temp != head){
printf("%d ",temp->date);
temp = temp->next;
}
printf("\n");
}
int doublelist_is_empty(doublelist * head){
return head->next == head ? 1 : 0;
}
int doublelist_head_del(doublelist * head){
if(doublelist_is_empty(head)){
printf("doublelist is empty\n");
return -1;
}
int value = head->next->date;
doublelist * temp = head->next;
head->next = temp->next;
temp->next->priv = head;
free(temp);
temp = NULL;
return value;
}
int main(int argc, const char *argv[])
{
doublelist * head = NULL;
head = doublelist_creat();
doublelist_head_insert(head,1);
doublelist_head_insert(head,2);
doublelist_head_insert(head,3);
doublelist_head_insert(head,4);
doublelist_head_insert(head,5);
doublelist_show(head);
printf("%d\n",doublelist_head_del(head));
doublelist_show(head);
printf("%d\n",doublelist_head_del(head));
doublelist_show(head);
printf("%d\n",doublelist_head_del(head));
doublelist_show(head);
printf("%d\n",doublelist_head_del(head));
doublelist_show(head);
printf("%d\n",doublelist_head_del(head));
doublelist_show(head);
printf("%d\n",doublelist_head_del(head));
doublelist_show(head);
return 0;
}