数据结构--栈

public class Stack<T> {

    private int top = -1;
    private int stackSize = 0;
    private T[] stack = null;

    Stack(int stackSize) {
        this.stackSize = stackSize;
        stack = (T[]) new Object[stackSize];
    }

    public void push(T t) {
        if (top < stackSize - 1) {
            stack[++top] = t;
            System.out.println("Success push into the stack, the elemetn is " + t + ".");
        } else {
            System.out.println("Sorry,can't push into the stack! The stack is full.");
        }
    }

    public T pop() {
        if (!isEmpty()) {
            return stack[top--];
        } else {
            System.out.println("Sorry,the stack is empty.");
            return null;
        }
    }

    public int size() {
        return top + 1;
    }

    public boolean isFull() {
        return stackSize == top + 1;
    }

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

    public static void main(String[] args) {
        Stack<String> stringStack = new Stack<>(5);
        for (int i = 0; i < 10; i++) {
            stringStack.push("str" + i);
        }

        System.out.println("The stack's size is " + stringStack.size() + ".");

        System.out.println("is full: " + stringStack.isFull());
        System.out.println("is empty: " + stringStack.isEmpty());

        for (int i = 0; i < 5; i++) {
            System.out.println("Stack pop a element, it is " + stringStack.pop() + ".");
        }
    }
}