数据结构与算法之七 栈

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace 检查括号是否匹配
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string expression;
            Stack<char> leftStack = new Stack<char>();

            expression = txtExpression.Text.Trim();

            //bool isRight = true;
            char c;
            for (int i = 0; i < expression.Length; i++)
            {
                c = expression[i];

                //如果是左括号
                if (IsLeft(c))
                {
                    leftStack.Push(c);
                }
                else if (IsRight(c))//如果是右括号
                {
                    //如果栈为空，表明有多余的右括号
                    if (leftStack.Count == 0)
                    {
                        txtResult.Text = "表达式错误：有多余的右括号"　+ c.ToString();
                        //isRight = false;
                        //break;
                        return;
                    }
                    else if (IsPiPei(leftStack.Peek(), c))
                    //判断取出的右括号是否与栈顶的左括号匹配
                    {
                        leftStack.Pop();
                    }
                    else
                    {
                        txtResult.Text = "表达式错误：右括号"
                                       + c.ToString() + "与左括号"
                                       + leftStack.Peek().ToString()
                                       + "不匹配";
                        //isRight = false;
                        //break;
                        return;
                    }
                }
            }

            if (leftStack.Count == 0) //&& isRight==true)
            {
                txtResult.Text = "表达式正确";
            }
            else
            {
                txtResult.Text = "表达式错误：有多余的左括号";
            }

        }

        //判断传入的字符是否是左括号
        bool IsLeft(char c)
        {
            if (c == '(' || c == '{' || c == '[')
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        //判断传入的字符是否是右括号
        bool IsRight(char c)
        {
            if (c == ')' || c == '}' || c == ']')
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        //判断传入的左右括号是否匹配
        bool IsPiPei(char left, char right)
        {
            //首先需要验证left为左括号，right为右括号
            if (IsLeft(left) && IsRight(right))
            {
                if (left == '(' && right == ')' ||
                   left == '{' && right == '}' ||
                   left == '[' && right == ']'
                   )
                {
                    return true;
                }
                else
                {
                    return false;
                }

            }
            else
            {
                throw new Exception("left应该为左括号，right应该为右括号");
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace 多进制转换
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnTransform_Click(object sender, EventArgs e)
        {
            string digitChar = "0123456789ABCDEF";
            int number;//存放10进制的数
            int d;//存放进制数
            Stack<char> stack = new Stack<char>();
            string result = null; //存放转换后的结果

            number = Int32.Parse(txtNumber.Text);
            d = Int32.Parse(txtD.Text);

            //第一步：将转换结果的每一位数放入栈中
            do
            {
                stack.Push(digitChar[number % d]);
                number = number / d;

            } while (number != 0);

            //第二步：将栈中存放的每一位数出栈，并添加到结果字符串末尾
            while (stack.Count != 0)
            {
                result = result + stack.Pop();
            }

            txtResult.Text = result;
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace 移除火车车厢
{
    public partial class Form1 : Form
    {
        Stack<char> resultStack;
        public Form1()
        {
            InitializeComponent();
        }

        private void btnRemove_Click(object sender, EventArgs e)
        {
            char removeChar;
            Stack<char> middleStack = new Stack<char>();
            if (resultStack == null)
            {
                resultStack = new Stack<char>();
                resultStack.Push('A');
                resultStack.Push('B');
                resultStack.Push('C');
                resultStack.Push('D');
                resultStack.Push('E');
            }

            removeChar = txtRemove.Text[0];

            while (resultStack.Count != 0)
            {
                //如果要移除的编号等于栈顶元素的编号
                if (removeChar == resultStack.Peek())
                {
                    resultStack.Pop();
                    break;
                }
                else//如果要移除的编号不等于栈顶元素的编号
                {
                    //将结果栈的栈顶元素出栈，并且将此元素放入中间栈中
                    middleStack.Push(resultStack.Pop());
                }
            }

            while (middleStack.Count != 0)
            {
                resultStack.Push(middleStack.Pop());
            }

            txtTrain.Text = "";
            foreach (char c in resultStack)
            {
                txtTrain.Text = txtTrain.Text + c.ToString();
            }
            
            //将结果字符串倒转
        }
    }
}