数据结构与算法读书笔记6----C# Stack类实现与应用

栈是著名的后进先出（LIFO）数据结构。

1、判断字符串是否是回文字符串。

2、十进制向多进制的转换。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace CStack
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(CStack.IsPalindrome("lixuejiao").ToString());
            Console.WriteLine(CStack.IsPalindrome("sees").ToString());
            Console.ReadLine();
        }
    }
    class CStack
    {
        private int p_index;
        private ArrayList list;
        private int count;

        public int Count
        {
            get { return list.Count; }
        }
        public CStack()
        {
            list = new ArrayList();
            p_index = -1;
        }
        public void Push(Object item)
        {
            list.Add(item);
            p_index++;
        }
        public object Pop()
        {
            object obj = list[p_index];
            list.RemoveAt(p_index);
            p_index--;
            return obj;
        }
        public void Clear()
        {
            list.Clear();
            p_index = -1;
        }
        public object Peek()
        {
            return list[p_index];
        }
        //判断字符串是否是回文字符串
        //2010.04.25
        public static bool IsPalindrome(string word)
        {
            CStack alist = new CStack();
            string ch;
            bool isPalindrome = true;
            for (int num = 0; num < word.Length; num++)
            {
                alist.Push(word.Substring(num,1));
            }
            int pos = 0;
            while (alist.Count > 0)
            {
                ch = alist.Pop().ToString();
                if (ch != word.Substring(pos, 1))
                {
                    isPalindrome = false;
                    break;
                }
                pos++;
            }
            if (isPalindrome)
            {
                Console.WriteLine(word + " is a palindrome");
            }
            else
            {
                Console.WriteLine(word +" is not a palindrome");
            }
            return isPalindrome;
        }
    }
}

 class Program
    {
        static void Main(string[] args)
        {
            int num, baseNum;
            Console.WriteLine("Enter a decimal number: ");
            num = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter a base: ");
            baseNum = Convert.ToInt32(Console.ReadLine());
            Console.Write(num+" converts to ");        
            Console.WriteLine("Base "+baseNum+" is: ");
            MulBase(num, baseNum);
            Console.ReadLine();
        }
        public static void MulBase(int n, int b)
        {
            Stack Digits = new Stack();
            do
            {
                Digits.Push(n%b);
                n/=b;
            }while(n!=0);
            while(Digits.Count>0)
            {
                Console.Write(Digits.Pop());
            }
        }
    }