private bool lbtInt(String tmpOpr, Op o, int i)
{
var n = LBT_EXP.Length;
for (int m = 0; m < n; m += 1)
{
if (LBT_EXP[m] == o.S)
{
// 操作符级别判断
if (LBT_INT[m] + 7 == RBT_INT[i])
{
oprStack.Pop();
if (stepList != null)
{
var t = (String)numStack.Peek();
String p = LBT_EXP[m] + t + RBT_EXP[m];
stepList.Add(new Items { K = mathExps, V = p, D = t });
mathExps = mathExps.Replace(p, t);
}
return true;
}
throw new Exception(String.Format("您输入的表达式不正确：{0}与{1}不匹配！", LBT_EXP[m], tmpOpr));
}
}
return false;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public String calculate()
{
if (string.IsNullOrEmpty(mathExps))
{
throw new Exception("表达式为空！");
}
mathExps = mathExps.Replace(" ", "").Trim();
var regex = new Regex("=[=]*=");
mathExps = regex.Replace(mathExps, "=");
if (mathExps == "" || mathExps == "=")
{
throw new Exception("请输入一个完整的运算表达式！");
}
if (mathExps.EndsWith("="))
{
mathExps = mathExps.Substring(0, mathExps.Length - 1);
}
int edx = mathExps.LastIndexOf('=') + 1;
mathExps = mathExps.Substring(edx, mathExps.Length - edx);
// 操作数堆栈
numStack = new Stack();
// numStack.Push("0");
// 操作符堆栈
oprStack = new Stack();
// oprStack.Push(new Op());
// 操作数缓冲区
var numBuf = new StringBuilder();
// 操作符缓冲区
var oprBuf = new StringBuilder();
// 表达式字符串
char[] expBuf = ('(' + mathExps + ')').ToCharArray();
// 临时字符串
String tmpOpr;
// 上一个字符（串）是否为操作符，true表示是；false表示否
lastIsOpr = false;
// 循环处理每一个表达式字符
foreach (char c in expBuf)
{
// 负号
if (lastIsOpr && (c == '-' || c == '+'))
{
if (oprBuf.Length != 0)
{
throw new Exception(String.Format("计算错误：未知运算符 “{0}”，请确认您输入计算式的正确性！", oprBuf));
}
lastIsOpr = false;
numBuf.Append(c);
continue;
}
// 操作数
if ((c >= '0' && c <= '9') || c == '.')
{
if (oprBuf.Length != 0)
{
throw new Exception(String.Format("计算错误：未知运算符 “{0}”，请确认您输入计算式的正确性！", oprBuf));
}
lastIsOpr = false;
numBuf.Append(c);
continue;
}
// e
if (c == 'ê')
{
if (oprBuf.Length != 0)
{
throw new Exception(String.Format("计算错误：未知运算符 “{0}”，请确认您输入计算式的正确性！", oprBuf));
}
lastIsOpr = false;
String ep = Decimal.Round(new Decimal(Math.E), decimals).ToString();
numBuf.Append(ep);
mathExps = mathExps.Replace("ê", ep);
continue;
}
// π
if (c == 'π')
{
if (oprBuf.Length != 0)
{
throw new Exception(String.Format("计算错误：未知运算符 “{0}”，请确认您输入计算式的正确性！", oprBuf));
}
lastIsOpr = false;
String ep = Decimal.Round(new Decimal(Math.PI), decimals).ToString();
numBuf.Append(ep);
mathExps = mathExps.Replace("π", ep);
continue;
}
// 操作符
tmpOpr = oprBuf.Append(c).ToString();
// 左括号
if (lbtExp(tmpOpr, oprBuf, numBuf))
{
continue;
}
// 右括号
if (rbtExp(tmpOpr, oprBuf, numBuf))
{
continue;
}
// 运算符运算
var j = OPR_EXP.Length;
for (int i = 0; i < j; i += 1)
{
if (OPR_EXP[i] == tmpOpr.ToLower())
{
lastIsOpr = ConstUI.OPR_FAC_EXP != tmpOpr;
// 清除当前操作符
oprBuf.Remove(0, oprBuf.Length);
// 左操作数不为空的情况下，左操作数入栈
if (numBuf.Length > 0)
{
numStack.Push(numBuf.ToString());
numBuf.Remove(0, numBuf.Length);
}
Items kvItem;
// 当前运算符
var newOpr = new Op(tmpOpr, OPR_INT[i]);
// 循环处理每一个操作符
while (true)
{
// 操作符级别判断
if (newOpr.L > ((Op)oprStack.Peek()).L)
{
oprStack.Push(newOpr);
break;
}
// 运算结果
kvItem = calculate(mathExps, decimals);
// 统计运算步骤
if (stepList != null)
{
stepList.Add(kvItem);
mathExps = mathExps.Replace(kvItem.V, kvItem.D);
}
}
break;
}
}
}
if (oprStack.Count > 0)
{
throw new Exception("表达式存在错误，系统无法计算！");
}
return numStack.Count != 0 ? Decimal.Round(Decimal.Parse((String)numStack.Pop()), decimals).ToString() : "";
}