onsider a Stack data structure that can perform $3$ operations Push$(),$ Pop$()$ and MultiPop$($k$).$ The Push and Pop cost is constant O$(1)$ and the MultiPop$($k$)$ cost is k$\text{'},$ where k$\text{'}$ is the minimum between k and s$,$ where s is the number of items in the Stack $($since you can't retrieve k elements from the stack if k $>$ s$).$

A potential function is given as the number of objects in the stack, where an empty stack has a potential function of $0,$ a stack with $1$ element has a potential function of $1,$ and so on$.$

What is the amortized cost for the Pop$(),$ Push$(),$ and MultiPop$()$ Operations?

Push $=2,$ Pop $=0,$ MultiPop$($k$)=0$

Push $=1,$ Pop $=1,$ MultiPop$($k$)=$ k

Push $=1,$ Pop $=1,$ MultiPop$($k$)=1$

Push $=1,$ Pop $=0,$ MultiPop$($k$)=1$