public TreeNode BuildTree(string s, ref int i)
{
i++;
if (s[i] == ')')
i++;
if (s[i] == '(')
{
i++;
AbstractOperation newTree = null;
if (s[i] == '+')
newTree = new Plus();
if (s[i] == '-')
newTree = new Minus();
if (s[i] == '*')
newTree = new Multiplication();
if (s[i] == '/')
newTree = new Division();
newTree.Left = this.BuildTree(s, ref i);
newTree.Right = this.BuildTree(s, ref i);
return newTree;
}
else if (Char.IsDigit(s[i]))
{
Operand newTree = new Operand(Convert.ToInt32(s[i]) - '0');
return newTree;
}
return null;
}
public void TestMethod1()
{
Plus testPlus = new Plus();
testPlus.Right = new Operand(1);
testPlus.Left = new Operand(2);
Assert.IsTrue(testPlus.Calculate() == 3);
}