C语言循环队列实现

typedef struct {
    int *arr;
    int front;
    int tail;
    int size;
} MyCircularQueue;


MyCircularQueue* myCircularQueueCreate(int k) {
    MyCircularQueue *obj = (MyCircularQueue *)malloc(sizeof(MyCircularQueue));
    obj->arr = (int *)malloc((k+1) * sizeof(int));
    obj->front = 0;
    obj->tail = 0;
    obj->size = k+1;

    return obj;
}

bool myCircularQueueEnQueue(MyCircularQueue* obj, int value) {
    if (obj->front == ((obj->tail + 1) % obj->size)) return false;

    obj->arr[(obj->tail)] = value;
    obj->tail = ((obj->tail) + 1) % obj->size;

    return true;
}

bool myCircularQueueDeQueue(MyCircularQueue* obj) {
    if (obj->front == obj->tail) return false;

    (obj->front) = ((obj->front) + 1) % obj->size;

    return true;
}

int myCircularQueueFront(MyCircularQueue* obj) {
    if (obj->front == obj->tail) return -1;

    return obj->arr[obj->front];
}

int myCircularQueueRear(MyCircularQueue* obj) {
    if (obj->front == obj->tail) return -1;

    int tmp = (obj->tail - 1 + obj->size) % obj->size;
    return obj->arr[tmp];
}

bool myCircularQueueIsEmpty(MyCircularQueue* obj) {
    return (obj->front == obj->tail);
}

bool myCircularQueueIsFull(MyCircularQueue* obj) {
    return obj->front == ((obj->tail + 1) % obj->size);
}

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);
*/

622. 设计循环队列 - 力扣（LeetCode）

记录下做题时候碰到的一些问题：
front指向队头元素，tail指向的则是队尾后一个元素（指示的是待插入的位置）。

由于是循环队列，实现的是时候注意取模。

取队尾元素的时候要注意不能对负数%。