How to convert infix expression to postfix expression using stack?, Algorithm for converting infix expression to postfix expression, solved examples for postfix conversion
Algorithm  Infix to Postfix using Stack
 1: Read the input string from left to right character by character.
 2: If the input character is an operand, then send it to the output.
 3: If the input character is an operator, then call PUSH operation based on the following;
 3a: If the stack is empty, then PUSH the character into the stack.
 3b: If the stack is not empty, then compare the priority of the top element in the stack with that of the new operator to be pushed.
 If the new operator is with higher priority, then PUSH the operator into stack.
 If the new operator is with lower priority, then POP the top element from the stack and add it to the output.
 Repeat 3b until stack is empty or the top element is with lower priority than the operator to be pushed.
 4: Repeat steps 2 to 3b for entire input string.
 5: If you have reached the end of the input string and the stack is empty then the output is your postfix expression.
Infix Expression: A + B * C
Input
character

Operation

Stack

Output

A

Empty

A


+

PUSH

+

A

B

+

AB


*

PUSH

+*

AB

C

+*

ABC


End of input

POP

ABC*+

Postfix expression: ABC*+
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