隊列的鏈式存儲結構

 

typedef int ElemType;
typedef struct QNode{
    ElemType data;
    Struct QNode *next;
}QNode,*pQNode;
typedef struct LinkQueue{
    pQNode front,rear;
}LinkQueue

void initQueue(LinkQueue *pQ){
    pQNode head = (pQNode)malloc(sizeof(QNode));

    head->next = NULL;
    pQ->front = head;
    pQ->rear = head;
}
bool EnQueue(LinkQueue *pQ,ElemType e){//尾插法類似於
    pQNode s = (pQNode)malloc(sizeof(QNode));
    if(!s){
        return false;
    }
    s->data = e;
    s->next = pQ->rear->next;//等價於s->next = NULL;
    pQ->rear->next = s;
    pQ->rear = s;
    return true;
}
bool DeQueue(LinkQueue *pQ,ElemType *e){
    pQNode p;

    if(pQ->front == pQ->rear){
        return false;
    }
    p = pQ->front->next;
    pQ->front->next = p->next;
    *e = p->data;
    if(pQ->rear == p){//如果只刪除的是最後一個元素！！！！則要重新給尾指針賦值
        pQ->rear == pQ->front;
    }
    free(p);
    return true;
}