简单的单链表实现栈

 

　判断括号是否配对完整.　

 class Node<T>
    {
        public T Item { get; set; }
        public Node<T> Next { get; set; }
    }

 

 class Stack3<T>
    {
        private Node<T> _first;
        private int _n;

        public int Count()
        {
            return _n;
        }

        public bool IsEmply()
        {
            return _first == null;
        }

        public void Push(T t)
        {
            Node<T> old = _first;
            _first = new Node<T>(){Item = t, Next = old};
            _n++;
        }

        public T Pop()
        {
            T  t = _first.Item;
            _first = _first.Next;
            _n--;
            return t;
        }

    }

　　

  class Program
    {
       private static Stack3<char> f = new Stack3<char>();

        static void Main(string[] args)
        {
     
            string str = "({[]}{}())";
            if (str.Length % 2 != 0)
            {
                Console.WriteLine("不对等");
                return;
            }

            for (int i = 0; i < str.Length; i++)
            {
                if (str[i] == '(' || str[i] == '{' || str[i] == '[')
                {
                    f.Push(str[i]);
                }
                else
                {
                    if (!IsA(str[i]))
                    {
                        Console.WriteLine("不对等");
                        return;
                    }
                }
            }

            Console.WriteLine("对等");
        }

        private static bool IsA(char ca)
        {
            bool flag = false;
            switch (ca)
            {
                case ')':
                    flag = f.Pop() == '(';
                    break;
                case '}':
                    flag = f.Pop() == '{';
                    break;
                case ']':
                    flag = f.Pop() == '[';
                    break;
                default:
                    break;
            }
          
            return flag;
        }
    }