[Swift][자료구조] Stack

Stack

// Stack
struct Stack<T>{
    private var stack: [T] = []
    
    public var count: Int{
        return stack.count
    }
    
    public var isEmpty: Bool{
        return stack.isEmpty
    }
    
    public func top() -> T?{
        return stack.last // 없으면 nil 반환
    }
    
    public mutating func push(_ element: T){
        stack.append(element)
    }
    
    public mutating func pop() -> T?{
        return stack.popLast() // 없으면 nil 반환
    }
}