Answer:
Hi
In the first scenario we have
S = []
then:
S=[1],
S=[2,1]
S=[3,2,1]
S=[2,1]
S=[4,2,1]
S=[2,1]
S=[1]
So when it's call the method peek to S, X will be assigned 1
Explanation:
Stack is a linear data structure which follows a particular order in which the operations are performed. The order may be LIFO(Last In First Out). There are many real-life examples of a stack. Consider an example of plates stacked over one another in the canteen. (Taken from wikipedia)
- The method push is to put the element on the top of the stack
- The method pop is take out the top element of the stack
- The method peek is to see what is the top element of the stack
