Input A B C * + D E / F * - Output (A+(B*C))-((D/E)*F)) Algorithm of Postfix to infix 1. Push postfix notation to the PostfixStack reverse order ( eg. push - * F / E D + * C B A) 2. while there are no data at PostfixStack 3. read one symbol from the PostfixStack 4. if the symbol is an operand 5. push it into the InfixStack 6. else 7. pop the top 2 values from the InfixStack 8. put the operator between two operand 9. Encapsulate the resulted string with parenthesis 10. if there is only one value in the stack That value in the stack is the desired Infix notation.