题目描述

有n人围成一圈，顺序排号。从第1个人开始报数（从1到3报数），凡报到3的人退出圈子，问最后留下的是原来的第几号的那位。

输入

初始人数n

输出

最后一人的初始编号

样例输入

3

样例输出

2 　使用无头循环单链表即可

1 #include 
     
       2 #include 
      
        3 typedef struct huan { 4 unsigned int a;  5 struct  huan *pNext;  6 }HUAN; 7 HUAN *Create(int n) { 8     HUAN *pHead, *pNew = NULL;    int i; 9     pHead = (HUAN*)malloc(sizeof(HUAN));10     pHead->a = 1;11     pHead->pNext = NULL;12     HUAN *cyclic = pHead;13         for (i = 2; i <= n; i++) {14         pNew = (HUAN*)malloc(sizeof(HUAN));15         pNew->a = i;16         pNew->pNext = NULL;17         cyclic->pNext = pNew;18         cyclic = cyclic->pNext;19     }20     cyclic->pNext = pHead;21     return pHead;22 }23 void Sort(HUAN *head) {24      HUAN *pbefore, *p;25      p = head; pbefore =NULL;26     while (p->pNext!=p) {27         for (int i = 1; i < 3; i++) {28             pbefore = p;29             p = p->pNext;30         }31         pbefore->pNext = p->pNext;32         free(p);33         p = pbefore->pNext;34         35 }36     printf("%d", p->a);37     free(p);38     39     40 }41 42 int main() {43     int n; HUAN *p;44     scanf("%d", &n);45     p = Create(n);46     Sort(p);47     48 }