c/c++语言开发共享C语言开发之循环队列的实现

c语言开发之循环队列的实现：c语言开发之循环队列的又该怎么实现呢？有什么方法呢？希望下面的文章对大家有所帮助。

运行环境：vs2015

  #include  #include  #include   //-------定义-----  typedef int elemtype;  typedef int status;  //------定义常量的值  #define ok 1  #define error 0  #define true 1  #define false 0  #define overflow 0  //----------结构体-----------  typedef struct {      elemtype *elem;  //存储空间基址      int front;      //队头位标      int rear;       //队尾位标，指示队尾元素的下一个位置      int maxsize;        //存储容量  }sqqueue;    //---------------接口声明--------  status initqueue_sq(sqqueue &q, int size);  //构造一个新队列  status destoryqueue_sq(sqqueue &q);         //销毁队列q，q不再存在  void clearqueue_sq(sqqueue &q);     //将q置为空队列  status queueempty_sq(sqqueue q);        //判断队列是否为空  int queuelength_sq(sqqueue q);      //返回队列q中的元素个数，即队列的长度  status gethead_sq(sqqueue q, elemtype e);   //若队列不空，则用e返回q的队列头元素  status enqueue_sq(sqqueue &q, elemtype e);//在队尾之后插入元素e，为新的队尾元素  status dequeue_sq(sqqueue &q, elemtype &e);     //出队    //----------初始化循环队列------  status initqueue_sq(sqqueue &q, int size) {      q.elem = (elemtype *)malloc(size * sizeof(elemtype));  //分配空间      if (q.elem == null) return overflow;    //分配空间失败      q.front = q.rear = 0;       //置队列为空队列      q.maxsize = size;   //赋值，设定存储空间长度      return ok;  }    //----------销毁循环队列---------  status destoryqueue_sq(sqqueue &q) {      q.front = q.rear = 0;       //置队为空      q.elem = null;      //把基址设为null      q.maxsize = 0;      free(q.elem);      return ok;  }    //------清空循环队列------  void clearqueue_sq(sqqueue &q) {      q.front = q.rear = 0;  }    //------判断循环队列是否为空------  status queueempty_sq(sqqueue q) {      if (q.front == q.rear)          return true;      else return false;  }    //------计算队列长度-----  int queuelength_sq(sqqueue q) {      if (q.rear >= q.front) {        //考虑两个都是0的情况          return (q.rear-q.front);              }else {          return (q.rear - q.front + q.maxsize + 1);  //q.rear-q.front+q.maxsize+1      }  }    //----若队列不空，则用e返回q的队列头元素---  status gethead_sq(sqqueue q, elemtype e) {      if (queueempty_sq(q) == false) {        //注意细节!          e = q.elem[q.front];          return e;      }      else {          return error;      }  }    //---在队尾之后插入元素e，为新的队尾元素---  status enqueue_sq(sqqueue &q, elemtype e) {      if (q.front == (q.rear + 1) % (q.maxsize)) {    //队满条件  少用一个元素空间          return overflow;      }      else {          q.elem[q.rear] = e;          q.rear = (q.rear + 1) % q.maxsize;  //q.rear循环+1          return e;      }  }    //----出队---  status dequeue_sq(sqqueue &q, elemtype &e) {      if (q.front == q.rear)      //队空          return error;      e = q.elem[q.front];      q.front = (q.front + 1) % q.maxsize;    //队头循环+1      return e;  }    void main() {      sqqueue q;      elemtype e = 0;      int length1;      //构造新队列      initqueue_sq(q, 8);      //入队      for (int i = 0; i < 12; i++) {          enqueue_sq(q, i+1);      }      length1 = queuelength_sq(q);      //遍历循环队列      for (int i = 0; i < length1; i++) {          printf("%dn", q.elem[i]);      }      //出队操作      printf("执行出队操作,出队3个元素：n");      for (int i = 0; i < 3; i++) {          dequeue_sq(q, e);      }      length1 = queuelength_sq(q);      for (int i = q.front; i < q.rear; i++) {          printf("%dn", q.elem[i]);      }      printf("执行入队操作,入队2个元素：n");      for (int i = 0; i < 2; i++) {          enqueue_sq(q, i + 1);      }      for (int i = q.front; i < q.maxsize; i++) {          printf("%dn", q.elem[i]);      }      for (int i = 0; i < q.rear; i++) {          printf("%dn", q.elem[i]);      }      printf("返回队头元素为:%dn", gethead_sq(q, e));  }