Postfix notation, also known as Reverse Polish Notation (RPN), is a mathematical notation in which every operator follows all of its operands. In postfix notation, expressions are written without the use of parentheses to indicate the order of operations. Instead, the operators are placed after their corresponding operands.
For example, consider the infix expression "3 + 4 * 5". In postfix notation, this expression would be written as "3 4 5 * +".
To evaluate expressions written in postfix notation, you can use a stack-based algorithm. You start scanning the expression from left to right, pushing operands onto a stack. When you encounter an operator, you pop the required number of operands from the stack, apply the operator, and then push the result back onto the stack. You continue this process until the entire expression is scanned, and the final result is the value left on the stack.
Postfix notation is particularly useful in computer science and calculators because it eliminates the need for parentheses and allows for straightforward parsing and evaluation of expressions. Additionally, it can be more efficient to evaluate postfix expressions compared to infix expressions.
