15.循环队列

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622. 设计循环队列 - 力扣（LeetCode）

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*
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);
*/