Infix to postfix conversion

 Step 1: Add " ) " to the end of the infix expression 

Step 2: Push " ( " on to the stack 

Step 3: Repeat until each character in the infix notation is scanned 

            - IF a " ( " is encountered, push it on the stack IF an operand (whether a digit or a character) is                      encountered, add it postfix expression. 

            - 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. 

           - IF an operator is encountered, then 

                      a. Repeatedly pop from stack and add each operator (popped from the stack) to the postfix expression which has the same precedence or a higher precedence than  0 .

                      b. Push the operator to the stack [END OF IF] 

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

Step 5: EXIT