Question

Let P be the postfix arithmetic expression: 7, 2, -, 1, 14, -, 1, 2, * Evaluate P using stack and showing the status of the stack at every step.

Answer 1

SNo.	Symbol	Action taken	Stack	intermediate outpt
1	7	operand, push	7
2	2	operand, push	7, 2
3	-	operator, pop twice		7-2=5
		Evaluate and push back	5
4	1	operand, push	5, 1
5	14	operand, push	5, 1, 14
6	-	operator, pop twice	5	1-14=-13
		Evaluate and push back	5, -13
7	1	operand, push	5, -13, 1	1*2=2
8	2	operand, push	5, -13, 1, 2
9	*	operator, pop twice	5, -13
		Evaluate and push back	5, -13, 2

As 2 is the Top most value so answer should be 2.