队列
后进后出的结构，时序结构抽象
区别与栈只有栈顶元素，队列由队首，队尾元素控制操作
插入 insert
void insert(Elem e); // 从队首添加
移除 remove
Elem remove(); // 从队尾移除
查看 peek
Elem peek();
队满
boolean isFull(); //
队空
boolean isEmpty();
Java代码实现
public class NewQueue<T> {
private int maxSize; // 队列最大长度
private T[] queueArray; // 数据存储数组
private int front; // 队首
private int rear; // 队尾
private int nItems; // 当前容量
public NewQueue(int maxSize) {
queueArray = (T[]) new Object[maxSize];
front = 0;
rear = -1;
nItems = 0;
}
public void insert(T t) {
if (rear == maxSize - 1) {
rear = -1;
}
queueArray[++rear] = t;
nItems++;
}
public T remove() {
T temp = queueArray[front++];
if (front == maxSize) {
front = 0;
}
nItems--;
return temp;
}
/**
* 获取队首元素
*/
public T peekFront() {
return queueArray[front];
}
/**
* 获取队尾元素
*/
public T peekRear() {
return queueArray[rear];
}
/**
* 队空
* @return
*/
public boolean isEmpty() {
return (nItems == 0);
}
/**
* 队满
* @return
*/
public boolean isFull() {
return (nItems == maxSize);
}
/**
* 返回队列实际使用长度
* @return
*/
public int size() {
return nItems;
}
}