​

 

队列

队列的顺序实现

1.队列的定义

#define MaxSize 10
typedef int ElemType;
typedef struct {
    ElemType data[MaxSize];
    int front, rear;
}SqQueue;

2.入队

bool EnQueue(SqQueue& Q, ElemType x) {
    if ((Q.rear+1)%MaxSize == Q.front)
        return false;
    Q.data[Q.rear] = x;
    Q.rear = (Q.rear + 1) % MaxSize;
    return true;
}

3.出队

bool DeQueue(SqQueue& Q, ElemType& x) {
    if (Q.front == Q.rear)
        return false;
    x = Q.data[Q.front];
    Q.front = (Q.front + 1) % MaxSize;
    return true;
}

4.获得队顶元素

bool GetHead(SqQueue& Q, ElemType& x) {
    if (Q.front == Q.rear)
        return false;
    x = Q.data[Q.front];
    return true;
}

队列的链式实现

1.队列的定义

typedef int ElemType;
typedef struct {
    ElemType data;
    LinkNode* next;
}LinkNode;
​
//链式队列
typedef struct {
    LinkNode* front,* rear;
}LinkQueue;

2.初始化

void InitQueue(LinkQueue& Q) {
    //初始时，front,rear都指向头节点
    Q.front = Q.rear = (LinkNode*)malloc(sizeof(LinkNode));
    Q.front->next = NULL;
}

3.判空

bool IsEmpty(LinkQueue& Q) {
    if (Q.front == Q.rear)
        return true;
    else
        return false;
}

4.入队

void EnQueue(LinkQueue& Q, ElemType x) {
    LinkNode* s = (LinkNode*)malloc(sizeof(LinkNode));
    s->data = x;
    s->next = NULL;
    Q.rear->next = s;
    Q.rear = s;
}

5.出队

bool DeQueue(LinkQueue& Q, ElemType& x) {
    if (Q.front == Q.rear)
        return false;         //空队
    LinkNode* p = Q.front->next;
    x = p->data;
    Q.front->next = p->next;
    if (Q.rear == p)
        Q.rear = Q.front;
    return true;
}

​