Question

Given an empty stack s, an input array a = {1,2,3,4}. What is printed when the following function is executed?

public void pushAndPop(Stack s, int[] a){

s.push(a[0]);

s.push(a[1]);

System.out.println(s.pop());

s.push(a[2]);

System.out.println(s.pop());

s.push(a[3]);

System.out.println(s.pop());

System.out.println(s.pop());

}

	A.2, 1, 4, 3
	B.2, 3, 1, 4
	C.1, 2, 3, 4
	D.2, 3, 4, 1

Answer 1

ANSWER:-

OPTION (D) 2, 3, 4, 1

Explanation :- first statement define that ,push first element of array in the stack means push 1 in the stack so top of the stack will be 1

second statemnet define that ,push second element of array in the stack , means push 2 in the stack so top of the stack will be 2

third statement pop the element from stack ,means pop the top element of stack .currently top element of stack is 2 so poped 2 in stack

fourth statement define that ,push third element of array in the stack , means push 3 in the stack so top of the stack will be 3

fifth statement pop the element from stack , means pop the top element of stack . currently top element of stack is 3 so poped 3 in stack

sixth statement define that ,push fourth element of array in the stack , means push 4 in the stack so top of the stack will be 4

seventh statement pop the element from stack , means pop the top element of stack . currently top element of stack is 4 so poped 4 in stack

eightth statement pop the element from stack , means pop the top element of stack . currently top element of stack is 1 so poped 1 in stack