Infix notation is a type of notation in which arithmetic expressions are written in a manner such that the operators appear in between the operands.
Postfix notation is a type of notation in which arithmetic expressions are written in a manner such that the operands appear before their operators.
Let' see how to convert Postfix expression to Infix expression:
Flowchart for Postfix to Infix Conversion:
Algorithm for Postfix to Infix Conversion:
Step 1: Start
Step 2: Read the Postfix expression from left to right.
Step 3: If the scanned character is an operand, then push it onto the Stack.
Step 4: If the scanned character is an operator, pop two operands from the
stack and concatenate them in order of 'operand1,operator, operand2'.
Push the result into the stack.
Step 5: Repeat steps 2-4 until the postfix expression ends.
Step 6: Pop all the rest elements of the stack if any.
Step 7: Stop
Let's take an example to understand cb+a*
- Reading from left to right, we scan the operands 'c' 'b' respectively and push it into the the stack.
- '+' is scanned and operands 'c', 'b' are popped and concatenated in form of c+b
- 'a' is then pushed into the stack.
- '*', is encountered and 'a' and string 'c+b' is popped and concatenated to give a string (c+b)*a
- Postfix form is obtained: (c+b)*a