栈和队列

1，stack

    先进后出

package com.aluo.structure.four;

public class Stack {
    private int maxSize;
    private long[] a;
    private int top;

    public Stack(int maxSize) {
        maxSize = maxSize;
        a = new long[maxSize];
        top = -1;
    }

    public void push(long value) {
        a[++top] = value;
    }

    public long pop() {
        return a[top--];
    }

    public long peek() {
        return a[top];
    }

    public boolean isEmpty() {
        return (top == -1);
    }

    public boolean isFull() {
        return (top == maxSize - 1);
    }
}

stack测试类

package com.aluo.structure.four;

public class TestStack {

    public static void main(String[] args) {
        Stack s = new Stack(5);
        s.push(1);
        s.push(2);
        s.push(3);
        s.push(7);
        s.push(7);
        while (!s.isEmpty()) {
            System.out.println(s.pop());
        }
    }

}

output：

2，队列

    先进先出

package com.aluo.structure.four;

public class Queue {
    private int maxSize;
    private long[] a;
    private int front;
    private int rear;
    private int nElements;

    public Queue(int maxSize) {
        maxSize = maxSize;
        a = new long[maxSize];
        front = 0;
        rear = -1;
        nElements = 0;
    }

    public void insert(long value) {
        if (rear == maxSize - 1) {
            rear = -1;
        }
        a[++rear] = value;
        nElements++;
    }

    public long remove() {
        long temp = a[front++];
        if (front == maxSize) {
            front = 0;
        }
        nElements--;
        return temp;
    }

    public boolean isEmpty() {
        return (nElements == 0);
    }

    public boolean isFull() {
        return (nElements == maxSize);
    }

    public long peekFront() {
        return a[front];
    }

    public int getNElement() {
        return nElements;
    }
}

队列测试类

package com.aluo.structure.four;

public class TestQueue {

    public static void main(String[] args) {
        int maxSize = 10;
        Queue q = new Queue(maxSize);
        q.insert(2);
        q.insert(23);
        q.insert(26);
        q.insert(23);
        q.insert(27);
        q.remove();
        q.remove();
        while (!q.isEmpty()){
            System.out.println(q.remove());
        }
    }

}

output：