栈----用数组实现栈

栈的定义

把线性表的插入和删除运算限制在表的一端进行。通常将表中允许进行运算端成为栈顶，不允许运算的另一端成为栈底。由于栈顶位置是动态变化的，需要设置栈顶指示器。

栈常见的运算

进栈或入栈、出栈或退栈

栈的特性

后进先出

说明：和线性表一样，栈也有两种存储方式：线性栈和链表栈

用数组实现栈—Java代码实现

public class Stack {
    int[] data; // 存数据的数组

    private int size;

    private int top;

    public Stack(int size){
        this.size = size;
        data = new int[size];
        top = -1;
    }

    public int getSize() {
        return size;
    }

    public int getTop() {
        return top;
    }

    /**
     * 判断栈是否为空
     * @return
     */
    public boolean isEmpty(){
        return top == -1;
    }

    /**
     * 判断栈是否满了
     * @return
     */
    public boolean isFull(){
        return top == size - 1;
    }

    /**
     * 入栈
     * @param i
     * @return
     */
    public boolean push(int i){
        if(isFull())
            return false;
        top++;
        data[top] = i;
        return true;
    }

    /**
     * 弹栈
     * @return
     * @throws Exception
     */
    public int pop() throws Exception {
        if(isEmpty())
            throw new Exception("The Stack is Empty...");
        return data[top--];
    }

    public int peek(){
        return data[top];
   }

   public int getMin() throws Exception {
        if(isEmpty())
            throw new Exception("The Stack is Empty...");
        int min = data[0];
        for(int i = 1; i <= top; i++){
            if(min > data[i]){
                min = data[i];
            }
        }
        return min;
   }

   public static void main(String[] args) throws Exception {
        Stack stack = new Stack(5);
        stack.push(2);
        stack.push(1);
        stack.push(3);
        System.out.println("The peek is " + stack.peek());
        System.out.println("The min is " + stack.getMin());

        while(!stack.isEmpty()){
            System.out.print(stack.pop());
        }
   }
}