Question

the postfix notation for (7-4)+2 is

Answer 1

Solution:

So the final postfix is : 74-2+

Let, X is an arithmetic expression written in infix notation. This algorithm finds the equivalent postfix expression Y.

1. Push “(“onto Stack, and add “)” to the end of X.
2. Scan X from left to right and repeat Step 3 to 6 for each element of X until the Stack is empty.
3. If an operand is encountered, add it to Y.
4. If a left parenthesis is encountered, push it onto Stack.
5. If an operator is encountered ,then:
   1. Repeatedly pop from Stack and add to Y each operator (on the top of Stack) which has the same precedence as or higher precedence than operator.
   2. Add operator to Stack.
      [End of If]
6. If a right parenthesis is encountered ,then:
   1. Repeatedly pop from Stack and add to Y each operator (on the top of Stack) until a left parenthesis is encountered.
   2. Remove the left Parenthesis.
      [End of If]
      [End of If]
7. END.