Swift builds the generic structure of the stack as well as the definition of the top (), push (), pop () definition functions

You can first use Swift to define the structure of the stack

Generic expression

struct Stack<t> {

var items = <T> ()

Defines the top function of the stack and returns the top element of the stack

Mutating func top ()->t{

Return items.last!

}

Define the push function to insert the item into the stack

mutating func push (item:t) {

Items.append (item)

}

Define the POP function and stack the top function back

Mutating func pop ()->t{

Return Items.removelast ()

}

}

Swift builds the generic structure of the stack as well as the definition of the top (), push (), pop () definition functions