/// <summary>
/// построение дерева разбора
/// </summary>
/// <param name="str">выражение</param>
private Operator BuildTree(string str)
{
TreeElement leftChild = null;
TreeElement rightChild = null;
int index = 0;
if (str[index] == '(')
{
string newStr = str.Substring(1, str.Length - 2);
str = newStr;
}
if (str[index] == ' ')
{
index++;
}
char operate = str[index];
index++;
if (str[index] == ' ')
{
index++;
}
if (str[index] == '(')
{
string newstr = GetExpression(str, ref index);
leftChild = BuildTree(newstr);
index++;
if (str[index] == ' ')
{
index++;
}
}
else
{
if (str[index] == ' ')
{
index++;
}
if ((str[index] >= '0') && (str[index] <= '9'))
{
leftChild = new Operand(Convert.ToInt32(str[index]) - Convert.ToInt32('0'));
}
index++;
if (str[index] == ' ')
{
index++;
}
}
if (str[index] == ' ')
{
index++;
}
if (str[index] == '(')
{
string newstr = GetExpression(str, ref index);
rightChild = BuildTree(newstr);
if (str[index] == ' ')
{
index++;
}
}
else
{
if (str[index] == ' ')
{
index++;
}
if ((str[index] >= '0') && (str[index] <= '9'))
{
rightChild = new Operand(Convert.ToInt32(str[index]) - Convert.ToInt32('0'));
}
index++;
if ((index < str.Length - 1) && (str[index] == ' '))
{
index++;
}
}
var newOperator = new Operator(operate);
newOperator.Left = leftChild;
newOperator.Right = rightChild;
return(newOperator);
}
/// <summary> /// построить дерево разбора /// </summary> /// <param name="expression">выражение</param> public void Build(string expression) => this.root = BuildTree(expression);
