设头指针的循环单向队列及其约瑟夫环应用

typedef struct QNode {int data;QNode *next;}QNode;typedef struct CLQueue {QNode *head;}CLQueue;void initCLQueue(CLQueue &Q) {//区别于只有一个结点的自闭环，空队列head->next设为NULLQ.head = new QNode;Q.head->data = NULL;Q.head->next = NULL;}bool isEmptyCLQueue(CLQueue Q) {//不采用Q.head->next==Q.head，因为那表示有且仅有一个结点if (Q.head->next==NULL)return true;elsereturn false;}int getCLQueueSize(CLQueue Q) {//获取队列长度if (isEmptyCLQueue(Q)) {return NULL;}if (Q.head->next == Q.head) {//只有一个结点时return 1;}int len = 1;QNode *tailNode = Q.head->next;while (tailNode != Q.head) {tailNode = tailNode->next;len++;}return len;}QNode* getCLQueueTail(CLQueue Q) {//获取队尾指针int len = getCLQueueSize(Q);if (len == 0) {return NULL;}if (len == 1) {return Q.head;}QNode* tailNode = Q.head;for (len; len > 1; len--) {tailNode = tailNode->next;}return tailNode;}void showCLQueue(CLQueue Q) {//遍历输出各结点值一遍int len = getCLQueueSize(Q);if (len == NULL) {cout << "Empty!" << endl;return;}QNode* showNode = Q.head;for (len; len > 0; len--) {cout << showNode->data<<" ";showNode = showNode->next;}cout << endl;return;}void enCLQueue(CLQueue &Q,int e) {//队尾入队QNode *tailNode = getCLQueueTail(Q);if (!tailNode) {//空插，head已经分配空间，无需再分配Q.head->data = e;Q.head->next = Q.head;return;}QNode *newNode = new QNode;newNode->data = e;if (tailNode == Q.head) {//只有一个结点Q.head->next = newNode;newNode->next = Q.head;return;}//多个结点tailNode->next = newNode;newNode->next = Q.head;return;}int deCLQueue(CLQueue &Q) {//队头出队QNode *tailNode = getCLQueueTail(Q);if (!tailNode) {//空删非法cout << "Error: empty delete!" << endl;return NULL;}int e;if (tailNode == Q.head) {//一个结点删除时，无需删除队列本身，只还原成空队列(断开头结点自闭环）e = Q.head->data;Q.head->data = NULL;Q.head->next = NULL;return e;}//多个结点,保存原队头，将队头后移，连接队尾与新队头，删除原队头QNode *delNode = Q.head;Q.head = Q.head->next;tailNode->next = Q.head;e=delNode->data;delete delNode;return e;}void rotateCLQueue(CLQueue &Q,int i) {//转动闭环，使得头指针指向第i个位置，队列元素保持不变int len = getCLQueueSize(Q);if (!len) {cout << "Error: empty rotate!" << endl;return;}if (len == 1) {return;}QNode *curNode = Q.head;for (i; i > 1; i--) {curNode = curNode->next;}Q.head = curNode;return;}

int joseph(int num,int first) {//约瑟夫环//num: 总人数，first:第一个报数位置CLQueue J; int last;initCLQueue(J);for (int i = 1; i <= num; i++) {enCLQueue(J, i);}showCLQueue(J);do {rotateCLQueue(J, first);last = deCLQueue(J);cout <<last<<" ";} while (!isEmptyCLQueue(J));cout << endl;return last;}