not A + B / C or 4 + 5 / 3

This is a simple infix to prefix or postfix Converter.

Enter the Infix expression below in box and press Convert

Postfix : | Prefix :

By Raj

Sr. no. | Expression | Stack | Postfix |
---|

Postfix

- Step 1: Add ")" to the end of the infix expression
- Step 2: Push "(" onto the stack
- Step 3: Repeat until each character in the infix notation is scanned
- 3.1: IF a "(" is encountered, push it on the stack
- 3.2: IF an operand ( whether a digit or a character) is encountered, add it postfix expression.
- 3.3: IF a ")" is encountered, then

a. Repeatedly pop from stack and add it to the postfix expression until a "(" is encountered.

b. Discard the "(". That is, remove the(from stack and do not add it to the postfix expression - 3.4: IF an operator O is encountered, then

a. Repeatedly pop from stack and add each operator ( popped from the stack) to the postfix expression which has equal or higher precedence than O

b. Push the operator O to the stack.

- Step 4: Repeatedly pop from the stack and add it to the postfix expression until the stack is empty
- Step 5: EXIT

Prefix

- Step 1: Reverse the infix string. Note that while reversing the string you must interchange left and right parentheses.
- Step 2: Obtain the postfix expression of the expression obtained from Step 1
using the above given postfix algorithm with slight change in
**Step 3.4**

IF an operator O is encountered, then

a. Repeatedly pop from stack and add each operator ( popped from the stack) to the postfix expression which has~~equal or~~higher precedence than O

- Step 3: Reverse the postfix expression to get the prefix expression