Algorithm to convert Infix to Postfix 

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 the given arithmetic expression.
    2. 
 
  2. Scan
     the given expression from left to right and repeat step 3 to 6 until the
     Stack is empty.
    3. 
 
  3. If
     an operand is encountered, add it to expression.
    4. 
 
  4. If a
     left parenthesis is encountered, push it onto Stack.
    5. 
 
  5. If
     an operator is encountered ,then:
    6. 
 
      
  
    1. Repeatedly
      pop from Stack and add to expression each operator (on the top of Stack)
      which has the same precedence as or higher precedence than operator.
      2. 
  
    2. Add
      operator to Stack.
      3. 
  
    3. [End
      of If]
      4. 
 
    
 
  6. If a
     right parenthesis is encountered ,then:
    7. 
 
      
  
    1. Repeatedly
      pop from Stack and add to expression each operator (on the top of Stack)
      until a left parenthesis is encountered.
      2. 
  
    2. Remove
      the left Parenthesis.
      3. 
  
    3. [End
      of If]
      4. 
  
    4. [End
      of If]
      5. 
 
    
 
  7. END.
    8.