/// <summary>
/// 树值计算
/// </summary>
/// <param name="root">要计算的节点</param>
/// <returns>节点计算结果值</returns>
private double Calculator(ExpressionNode root)
{
double result = default(double);
double leftValue = default(double);
double rightValue = default(double);
if (root == null)
{
return(result);
}
if (root.Left != null)
{
if (!root.Left.IsLeaf)
{
leftValue = Calculator(root.Left);
}
else
{
leftValue = root.Left.Value;
}
}
if (root.Right != null)
{
if (!root.Right.IsLeaf)
{
rightValue = Calculator(root.Right);
}
else
{
rightValue = root.Right.Value;
}
}
if (!BaseCalate.IsOperator(root.Operator))
{
result = root.Value;
}
else
{
result = BaseCalate.BaseCal(leftValue, rightValue, root.Operator.ToString());
}
return(result);
}
/// <summary>
/// 无括号的加减乘除混合表达式运算
/// </summary>
/// <param name="expression">要计算的表达式字符串</param>
/// <returns>表达式节点树</returns>
private ExpressionNode BlendExpressionParse(string expression)
{
int startSubExpressionIndex = 0;
int endSubExpressionIndex = -1;
string subExpression = string.Empty;
double subExpressionValue = 0.0d;
if (expression[0] == Operators.Subtraction)
{
expression = "0" + expression;
}
while (true)
{
for (int i = 0; i < expression.Length; i++)
{
if (expression[i] == Operators.Multiply || expression[i] == Operators.Division)
{
if (i + 1 == expression.Length)
{
endSubExpressionIndex = i + 1;
}
else
{
for (int j = i + 1; j < expression.Length; j++)
{
if (BaseCalate.IsOperator(expression[j]))
{
endSubExpressionIndex = j;
break;;
}
}
if (endSubExpressionIndex == -1)
{
endSubExpressionIndex = expression.Length;
}
}
subExpression = expression.Substring(startSubExpressionIndex, endSubExpressionIndex - startSubExpressionIndex);
subExpressionValue = BaseCalate.BaseCal(subExpression);
expression = expression.Remove(startSubExpressionIndex, endSubExpressionIndex - startSubExpressionIndex);
expression = expression.Insert(startSubExpressionIndex, subExpressionValue.ToString());
endSubExpressionIndex = -1;
break;
}
if (expression[i] == Operators.Add || expression[i] == Operators.Subtraction)
{
startSubExpressionIndex = i + 1;
}
}
if (!expression.Contains(Operators.Multiply) && !expression.Contains(Operators.Division))
{
break;
}
}
ExpressionNode root = BaseExpressionParse(expression);
return(root);
}
