The expression (a - b)* (c + d)is equivalent to which of the following postfix expressions?
A) a b c d - + *
B) a b - c d + *
C) a b - + c d *
D) - + * a b c d

Question

Quizplus · Accepted Answer

To convert the given infix expression to postfix, we follow the below steps:
1. Scan the expression from left to right.
2. If we find an operand (variable), we output it to the postfix expression.
3. If we find an operator, we push it onto the stack if it has higher precedence than the operator on top of the stack, otherwise keep popping the stack and outputting the popped operators until we find an operator with lower precedence than the current operator. Then, push the current operator onto the stack.
4. After scanning the expression, if there are any operators left on the stack, pop them and output them to the postfix expression.

Using the above steps, we get the following postfix expression for (a-b)*(c+d):
a b - c d + *

Hence, the correct choice is B.

The Expression (A - B)* (C + D)is Equivalent to Which