C# 栈的实现

早前写得栈的实现，基本功能都有。

代码：

    /// <summary>
    /// 栈
    /// </summary>
    public class Stack
    {
        private object[] data; //用data数组来储存数据

        private int size;      //栈的大小

        private int top;       //top指针

        public object this[int loc]
        {
            get { return loc >= 0 && loc <= top ? data[loc] : null; }
        }

        /// <summary>
        /// 当前栈中元素个数
        /// </summary>
        public int Length
        {
            get { return this.top + 1; }
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="size"></param>
        public Stack(int size)
        {
            if (size>=0)
            {
                this.data = new object[size];
                this.size = size;
                this.top = -1;        //初始top指针赋-1
            }
            else
            {
                this.data = null;
                this.size = 0;
                this.top = -1;
            }
        }
        
        /// <summary>
        /// 是否空
        /// </summary>
        /// <returns></returns>
        public bool isEmpty()
        {
            return this.top == -1;
        }

        /// <summary>
        /// 是否满
        /// </summary>
        /// <returns></returns>
        public bool isFull()
        {
            return this.top == this.size - 1;
        }

        /// <summary>
        /// 压栈
        /// </summary>
        /// <param name="elem"></param>
        public void Push(object elem)
        {
            if (this.isFull())
            {
                throw new Exception("Stack is full!");
            }
            this.top++;
            this.data[this.top] = elem;
        }

        /// <summary>
        /// 出栈
        /// </summary>
        /// <returns></returns>
        public object Pop()
        {
            if (this.isEmpty())
            {
                throw new Exception("Stack is empty!");
            }
            object elem = this.data[this.top];
            this.top--;
            return elem;
        }

        /// <summary>
        /// 获取栈顶元素
        /// </summary>
        /// <returns></returns>
        public object getTop()
        {
            if (this.isEmpty())
            {
                throw new Exception("Stack is empty!");
            }
            return this.data[this.top];
        }

        /// <summary>
        /// 清空
        /// </summary>
        public void Clear()
        {
            this.top = -1;
        }
    }