GATE 2019 - P&DS Quiz-4 (Stack ) (App update required to attempt this test)

Consider the following expression :

A+B*C*D^E/F-G

Convert this expression into postfix expression and then evaluate it using the stack. We have different stacks available of different sizes. What is the optimal size of stack that must be used to evaluate the above postfix expression _______ .

Consider the implementation of multiple stacks in single array S of size P from index 0 to P-1. Size of each stack is Q. The following function PUSH(), used to PUSH data x on to a particular stack I where is used as top variable for stack i(i indicates stack number.)
PUSH (S, P, Q, T_i, x)
{
if (_______A_______)
{
printf(“stack overflow”);
exit (1);
}
else
T_i ++;
S[ T_i ] = x_;
}
Stack 0 store element from 0 to Q – 1, stack 1 stores from q to 2Q -1, and similarly other stack will store elements. Which of the following is the correct expression to replace A in the function?

Suppose you have a stack in which the values 1 through 5 must be pushed on the stack in that order, but that an item on the stack can be popped at any time. Give a sequence of push and pop operations such that the values are popped in the following order:
(a) 2, 4, 5, 3, 1
(b) 1, 5, 4, 2, 3
(c) 1, 3, 5, 4, 2
It might not be possible in which case?