15.循环队列
622. 设计循环队列 - 力扣(LeetCode)
* 解题思路: 通过一个定长数组实现循环队列 入队:首先要判断队列是否已满,再进行入队的操作,入队操作需要考虑索引循环的问题,当索引越界,需要让它变成最小值 出队:首先要判断队列是否为空,再进行出队操作,出队也需要考虑索引循环的问题 判空: 队头 == 队尾 判满: 队尾 + 1 == 队头 */
typedef struct
{int*_arr;int _front;int _rear;int k;
} MyCircularQueue;bool myCircularQueueIsEmpty(MyCircularQueue* obj)//是否为空
{if(obj->_front==obj->_rear){return true;}else{return false;}
}bool myCircularQueueIsFull(MyCircularQueue* obj)
{if( (obj->_rear+1)%(obj->k+1)==obj->_front){return true;}else{return false;}
}MyCircularQueue* myCircularQueueCreate(int k)
{MyCircularQueue*Queue=(MyCircularQueue*)malloc(sizeof(MyCircularQueue));if(Queue==NULL){perror("malloc");exit(-1);}int*arr=(int*)malloc(sizeof(int)*(k+1));if(arr==NULL){perror("malloc");exit(-1);}Queue->_arr=arr;Queue->_front=Queue->_rear=0;Queue->k=k;return Queue;
}bool myCircularQueueEnQueue(MyCircularQueue* obj, int value) //入队
{if(myCircularQueueIsFull(obj)==false ){obj->_arr[obj->_rear]=value;obj->_rear++;obj->_rear= obj->_rear%(obj->k+1);return true;}else{return false;}
}bool myCircularQueueDeQueue(MyCircularQueue* obj) //出队
{if(myCircularQueueIsEmpty(obj)==false ){obj->_front++;obj->_front= obj->_front%(obj->k+1);return true;}else{return false;}
}int myCircularQueueFront(MyCircularQueue* obj)
{if(myCircularQueueIsEmpty( obj)==true){return -1;}else{return obj->_arr[obj->_front];}
}int myCircularQueueRear(MyCircularQueue* obj)
{if(myCircularQueueIsEmpty( obj)==true){return -1;}else{return obj->_arr[(obj->_rear+obj->k)%(obj->k+1)];}}void myCircularQueueFree(MyCircularQueue* obj)
{free(obj->_arr);free(obj);
}/*** Your MyCircularQueue struct will be instantiated and called as such:* MyCircularQueue* obj = myCircularQueueCreate(k);* bool param_1 = myCircularQueueEnQueue(obj, value);* bool param_2 = myCircularQueueDeQueue(obj);* int param_3 = myCircularQueueFront(obj);* int param_4 = myCircularQueueRear(obj);* bool param_5 = myCircularQueueIsEmpty(obj);* bool param_6 = myCircularQueueIsFull(obj);* myCircularQueueFree(obj);
*/