Question

In the following code I give, everytime it will output ")".

Input :

((A+B)*((C-D)/(E^F)))

Expected output :

((A+B)*((C-D)/(E^F)))
A+B*C-D/E^F

my output :

)

My code :

class Et:
  def __init__(self , value):
        self.value = value
        self.left = None
        self.right = None
  def isOperator(c):
    if (c == '+' or c == '-' or c == '*' or c == '/' or c == '^' ):
        return True
    else:
        return False
  def inorder(t):
    if t is not None:
        inorder(t.left)
        print (t.value)
        inorder(t.right)
  def constructTree(postfix):
    stack = []
    for char in postfix :
        if not isOperator(char):
            t = Et(char)
            stack.append(t)
        else:
            t = Et(char)
            t1 = stack.pop()
            t2 = stack.pop()
            t.right = t1
            t.left = t2
            stack.append(t)
    t = stack.pop()
    return t
postfix = "((A+B)*((C-D)/(E^F)))"
r = constructTree(postfix)
inorder(r)

Answer 1

Whatever code you have written does not take care of parenthesis like '(' or ')'. In order to get the correct output, you would need to take care of the parenthesis separately.

Only after you take care of them, you will get the desired output for the expression tree.