最近频繁解决计算方面的问题，其中就有实现字符串表达式计算返回结果值需求，通过使用栈实现，需要定义运算符号优先级，其它就不细说，代码如下：
csStack.cs:
using System;
namespace PYHB
{
/// <summary>
/// 栈堆设定。
/// 日期：2005-05-17
/// </summary>
public class clsStack
{
private long Top; //栈最大序号
private int MaxSize; // MaxSize 栈的容量
private string[] Element;
public clsStack()
{
//
// TODO: 在此处添加构造函数逻辑
//
Top=-1;
}
/// <summary>
/// 设定栈大最大容量
/// </summary>
/// <param name="Size"></param>
public void Initialize(int Size)
{
MaxSize=Size;
Element=new string[Size];
}
/// <summary>
/// 入栈
/// </summary>
/// <param name="strItem"></param>
public void Push(string strItem)
{
if(!IsFull())
{
Top=Top+1;
Element[Top] = strItem;
}
}
/// <summary>
/// 出栈
/// </summary>
/// <returns></returns>
public string Pop()
{
string strRtn=" ";
if(!IsEmptly())
{
strRtn = Element[Top];
Top=Top-1;
}
return strRtn;
}
public string GetTop()
{
string strRtn=" ";
if(!IsEmptly())
{
strRtn = Element[Top];
}
return strRtn;
}
public bool IsFull()
{
bool IsFull=Top==(MaxSize-1)?true:false;
return IsFull;
}
public void MakeEmptly()
{
Top = -1;
}
public bool IsEmptly()
{
bool IsEmptly=Top==-1?true:false;
return IsEmptly;
}
}
}
calculate.cs
using System;
using System.Text;
using System.Windows.Forms;
namespace PYHB
{
/// <summary>
/// 字符串表达式计算实现,返回计算结果字符数组
/// 日期：2005-05-17
/// </summary>
public class Calculate
{
private clsStack S=new clsStack();
public Calculate()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
/// <summary>
/// 根据数字表达式字符串数组，返回计算结果字符数组
/// </summary>
/// <param name="strSoure">strSour 中缀表达式字符串，头部没有“#”，尾部需要加上“#”</param>
/// <returns>计算结果</returns>
public string[] Run(string[] strSoure)
{
if(strSoure==null)
{
return null;
}
string[] dRtn=new string[strSoure.Length];
for(int k=0;k<strSoure.Length;k++)
{
string[] ATemp;
string strRPN;
strRPN=GetRPN(strSoure[k]);
try
{
ATemp=strRPN.Trim().Split(' ');
for(int i=0;i<ATemp.Length;i++)
{
if(sysFun.IsNumber(ATemp[i]))
S.Push(ATemp[i]);
else
DoOperate(ATemp[i]);
}
dRtn[k]=S.Pop();
}
catch{}
}
return dRtn;
}
/// <summary>
/// Run 返回后缀表达式
/// strSour 中缀表达式字符串，头部没有“#”，尾部需要加上“#”
/// String 后缀表达式字符串，头尾都没有“#”
/// </summary>
/// <param name="strSource"></param>
/// <returns></returns>
private string GetRPN(string strSource)
{
string[] ATemp;
string strRPN="",Y;
ATemp=strSource.Trim().Split(' ');
S.Initialize(ATemp.Length);
S.MakeEmptly();
S.Push("#");
try
{
for(int k=0;k<ATemp.Length;k++)
{
//数字
if(sysFun.IsNumber(ATemp[k]))
{
strRPN += " "+ATemp[k];
}
//字符
else
{
if(ATemp[k]==")")
{
do
{
Y=S.Pop();
if(Y!="(")
strRPN += " "+Y;
}
while(Y.Trim()!="(");
}
else
{
do
{
Y = S.Pop();
if (GetISP(Y) > GetICP(ATemp[k]))
strRPN += " "+Y;
}
while(GetISP(Y) > GetICP(ATemp[k]));
S.Push(Y);
S.Push(ATemp[k]);
}
}
}
do
{
Y=S.Pop();
if(Y!="#")
strRPN+=" "+Y;
}
while(Y!="#");
}
catch{}
return strRPN;
}
#region 运算符优先级定义
private enum isp
{
s35 = 0,
s40 = 1,
s94 = 7,
s42 = 5,
s47 = 5,
s37 = 5,
s43 = 3,
s45 = 3,
s41 = 8
}
private enum icp
{
s35 = 0,
s40 = 8,
s94 = 6,
s42 = 4,
s47 = 4,
s37 = 4,
s43 = 2,
s45 = 2,
s41 = 1
}
private int GetISP(string a1)
{
Encoding ascii =Encoding.ASCII;
byte[] a=ascii.GetBytes(a1);
switch(Convert.ToInt32(a[0]))
{
case 35:
return (int)isp.s35;
case 40:
return (int)isp.s40;
case 94:
return (int)isp.s94;
case 42:
return (int)isp.s42;
case 47:
return (int)isp.s47;
case 37:
return (int)isp.s37;
case 43:
return (int)isp.s43;
case 45:
return (int)isp.s45;
case 41:
return (int)isp.s41;
default:
return (int)isp.s35;
}
}
private int GetICP(string a1)
{
Encoding ascii =Encoding.ASCII;
byte[] a=ascii.GetBytes(a1);
switch(Convert.ToInt32(a[0]))
{
case 35:
return (int)icp.s35;
case 40:
return (int)icp.s40;
case 94:
return (int)isp.s94;
case 42:
return (int)icp.s42;
case 47:
return (int)icp.s47;
case 37:
return (int)icp.s37;
case 43:
return (int)icp.s43;
case 45:
return (int)icp.s45;
case 41:
return (int)icp.s41;
default:
return (int)icp.s35;
}
}
#endregion
/// <summary>
/// 判断是否存在左右数字，并且复制
/// </summary>
/// <param name="dLeft">左数值</param>
/// <param name="dRight">右的数值</param>
/// <returns>是否成功</returns>
private bool GetTwoItem(ref decimal dLeft,ref decimal dRight)
{
bool bRtn=true;
try
{
if(S.IsEmptly())
return false;
else
dRight = Convert.ToDecimal(S.Pop());
if(S.IsEmptly())
return false;
else
dLeft = Convert.ToDecimal(S.Pop());
}
catch
{
}
return bRtn;
}
/// <summary>
/// 根据运算符号计算，并且把计算结果以字符形式填充入栈
/// </summary>
/// <param name="op"></param>
private void DoOperate(string op)
{
decimal NumLeft=0,NumRight=0;
bool r;
r=GetTwoItem(ref NumLeft,ref NumRight);
if(r)
{
switch(op.Trim())
{
case "+":
S.Push((NumLeft+NumRight).ToString());
break;
case "-":
S.Push((NumLeft-NumRight).ToString());
break;
case "*":
S.Push((NumLeft*NumRight).ToString());
break;
case "/":
if(NumRight==0)
S.Push("0");
else
S.Push((NumLeft/NumRight).ToString());
break;
}
}
}
}
}
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