Question

A stack is implemented as a linear array A[0...N-1]. A programmer writes thefunction given below to pop out an element from the stack,function POP( top, N){if (X){top=top-1)elseho{print "Underflow"}return top}what should substitute the condition x​

Answer 1

Answer:

top >= 0

Explanation:

we need to check if stack is empty or not.

Answer 2

X = top>=0 && top<N

Explanation:

function POP( top, N){

   if (X){

       top=top-1

   }else{

       print "Underflow"

   }

   return top

}

• when we pop from the stack, then the pointer will move one step down.

• So we have to check the border condition that the pointer top is non-negative or not

• and also the top is above the length of the stack or not.

• Thus, X = top>=0 && top<N