Question

Evaluate the following postfix expression: 6 4 + 3 10 * 2 2 2 - + * +

What is the highest number of elements on our stack at any one time?

can you please explain the answer for me ?

Answer 1

6 4 + 3 10 * 2 2 2 - + * +
--------------------------------
stack: []
push 6
stack: [6]
push 4
stack: [6 4]
pop, 6 and 4, push 6+4 = 10
stack: [10]
push 3
stack: [10 3]
push 10
stack: [10 3 10]
pop, 3 and 10, push 3*10 = 30
stack: [10 30]
push 2
stack: [10 30 2]
push 2
stack: [10 30 2 2]
push 2
stack: [10 30 2 2 2]
pop, 2 and 2, push 2-2 = 0
stack: [10 30 2 0]
pop, 2 and 0, push 2+0 = 2
stack: [10 30 2]
pop, 30 and 2, push 30*2 = 60
stack: [10 60]
pop, 10 and 60, push 10+60 = 70
stack: [70]

value of this expression is 70
and we can see that maximum size of stack is 5