1 /**循环链表解决约瑟夫环问题
 2  * 问题：约瑟夫环
 3  * 有编号从1到N的N个人坐成一圈报数，从第K个人开始报数，报到M的人出局，
 4  * 下一位再从1开始报数，如此持续，直止剩下一位为止，报告此人的编号X。
 5  * 输入N,K,M，求出X。
 6  */
 7
 8 #include <iostream>
 9 using namespace std;
10
11 struct MyNode
12 {
13     MyNode(int a_data):m_data(a_data),m_pNext(NULL) {}
14
15     int    m_data;
16     MyNode *m_pNext;
17 };
18
19 class Josephus
20 {
21 public:
22     Josephus(int a_N, int a_K, int a_M):m_N(a_N),m_K(a_K),m_M(a_M)
23     {
24         createList();
25         outputList();
26     }
27
28 protected:
29     void createList();
30     void outputList();
31
32 private:
33     MyNode *m_pHead;//循环链表的头节点
34     int    m_N;     //链表节点个数
35     int    m_K;     //第一个报数人的序号
36     int    m_M;     //报数出局的数
37 };
38
39 void Josephus::createList()
40 {
41     MyNode *pre = NULL;
42     MyNode *cur = NULL;
43     MyNode *p = new MyNode(1);
44     m_pHead = p;
45     cur = p;
46     for (int i=2; i<=m_N; i++)
47     {
48         p = new MyNode(i);
49         pre = cur;
50         cur = p;
51         pre->m_pNext = cur;
52     }
53     cur->m_pNext = m_pHead;
54
55     int n=m_N;
56     p = m_pHead;
57     while (n--)
58     {
59         cout << p->m_data << ",";
60         p = p->m_pNext;
61     }
62     cout << endl;
63 }
64
65 void Josephus::outputList()
66 {
67     MyNode *pre = NULL;
68     MyNode *cur = m_pHead;
69     m_K--;
70     while (m_K--)            //寻找第K个人（开始报数的人）
71     {
72         pre = cur;
73         cur = cur->m_pNext;
74     }
75     while (m_N--)            //输出链表中所有的节点值
76     {
77         int s = m_M-1;
78         while (s--)            //寻找间隔M的人
79         {
80             pre = cur;
81             cur = cur->m_pNext;
82         }
83         MyNode *p = cur;
84         cout << p->m_data << ",";
85         cur = cur->m_pNext;    //删除节点的过程
86         pre->m_pNext = cur;
87         delete p;
88         p=NULL;
89     }
90 }
91
92 int main()
93 {
94     Josephus josephus(100,5,5);
95     return 0;
96 }