02.C#集合

public interface IEnumerable
{
    IEnumerator GetEnumerator();
}

public interface IEnumerator
{
    object Current { get; }
    bool MoveNext();
    void Reset();
}

class Program
{
    static void Main(string[] args)
    {
        List<int> list = new List<int>();//List<int> list = new List<int>(3)
        for (int i = 0; i < 1025; i++)
        {
            if (list.Count == (list.Capacity))
            {
                Console.WriteLine("容量使用量："+list.Count + "/" + list.Capacity);
            }
            list.Add(i);
        }
        Console.WriteLine("容量使用量：" + list.Count + "/" + list.Capacity);
        list.TrimExcess();//调整容量
        Console.WriteLine("容量使用量：" + list.Count + "/" + list.Capacity);
        Console.Read();
    }
}

List<int> list = new List<int>() { 1,2,3,4,5,6,7,8,9,0};
List<string> list = new List<int>() { "aa", "bb", "cc" };

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>();
        list.AddRange(new string[]{"aa","bb","cc"});//添加数组
        list.AddRange(list);//添加集合
        foreach (string s in list)
        {
            Console.WriteLine(s);
        }
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "aa", "bb", "ff" };
        list.Insert(2, "cc");//插入元素
        list.InsertRange(3, new string[] { "dd", "ee" });//插入集合
        foreach (string s in list)
        {
            Console.WriteLine(s);
        }
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "aa", "bb", "cc" };
        Console.WriteLine(list[1]);//访问第1个位置上的元素，下标从0开始
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "aa", "bb", "cc" };
        list.ForEach(temp => Console.WriteLine("元素：" + temp));
        //也可使用： list.ForEach(Console.WriteLine);
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "12", "123", "1234", "12345" };
        //删除长度小于4的元素
        list.RemoveAll(x => { bool flag = x.Length < 4; return flag; });
        list.ForEach(Console.WriteLine);
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "12", "123", "1234", "12345" };
        //搜索长度小于4的元素
        list=list.FindAll(x => { bool flag = x.Length < 4; return flag; });
        list.ForEach(Console.WriteLine);
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "12", "123", "1234", "12345" };
        //按字符串长度排序
        list.Sort((x, y) => { return y.Length - x.Length; });
        list.ForEach(Console.WriteLine);
        Console.Read();
    }
}

public sealed delegate TOutput Converter<TInput, TOutput>(TInput from)

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "12", "123", "1234", "12345" };
        //把字符串转换成数字(String->int)
        List<int> array = list.ConvertAll<int>(temp => Int32.Parse(temp));
        array.ForEach(temp => Console.WriteLine((temp + 1)));
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<int> list = new List<int>() {1,3,5,7,9};
        IEnumerable<string> array = list.Select<int, string>(x => (x * x).ToString());
        foreach(string s in array)
        {
            Console.WriteLine(s);
        }
        Console.Read();
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string> { "1", "12", "123", "1234" };
        //查询长度小于3的元素
        IEnumerable<string> query = list.Where(temp => temp.Length < 3);
        foreach (string s in query)
        {
            Console.WriteLine(s);
        }
        Console.Read();
    }
}

3.常见集合的特性

class Program
{
    static void Main(string[] args)
    {
        Queue<string> queue = new Queue<string>();
        for (int i = 1; i < 5; i++)
        {
            queue.Enqueue(i.ToString());//在尾部添加元素
        }
        PrintQueue(queue);//输出元素
        string s = queue.Dequeue();//读取并删除头部元素
        Console.WriteLine("读取并删除头部元素:" + s);
        queue.Enqueue("5");//在尾部添加元素
        s = queue.Peek();//读取头部元素
        Console.WriteLine("读取头部元素:" + s);
        PrintQueue(queue);//输出元素
        Console.Read();
    }
    //输出元素
    private static void PrintQueue(Queue<string> q)
    {
        IEnumerable<string> list = q.Where(t => true);
        foreach (string t in list)
        {
            Console.WriteLine(t);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        Stack<string> stack = new Stack<string>();
        for (int i = 1; i < 5; i++)
        {
            stack.Push(i.ToString());//入栈
        }
        PrintStack(stack);//输出元素
        string s = stack.Pop();//读取并删除栈顶元素
        Console.WriteLine("读取并删除栈顶元素:" + s);
        s = stack.Peek();//只读取栈顶元素
        Console.WriteLine("只读取栈顶元素:" + s);
        PrintStack(stack);//输出元素
        Console.Read();
    }
    //输出元素
    private static void PrintStack(Stack<string> s)
    {
        IEnumerable<string> list = s.Where(t => true);
        foreach (string t in list)
        {
            Console.WriteLine(t);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        LinkedList<int> link = new LinkedList<int>();
        LinkedListNode<int> node;
        for (int i = 0; i < 10; i++)
        {
            node = new LinkedListNode<int>(i);
            if (i % 2 == 0)
            {
                link.AddFirst(node);//从头部添加节点
            }
            else
            {
                link.AddLast(node);//从尾部添加节点
            }
        }
        PrintLink(link);//输出元素
        Console.Read();
    }
    //输出元素
    private static void PrintLink(LinkedList<int> l)
    {
        IEnumerable<int> list = l.Where(t => true);
        foreach (int t in list)
        {
            Console.WriteLine(t);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        SortedList<string, string> sort = new SortedList<string, string>();
        sort.Add("K1", "V1");//Add方法添加元素
        sort["K2"] = "V2";//索引器添加元素
        PrintSorted(sort);//输出元素
        Console.WriteLine("是否存在[K3]：" + sort.ContainsKey("K3"));
        string value = null;
        Console.WriteLine("是否存在[K2]：" + sort.TryGetValue("K2", out value));
        Console.WriteLine("[K2]的值：" + value);
        Console.Read();
    }
    //输出元素
    private static void PrintSorted(SortedList<string, string> s)
    {
        IEnumerable<KeyValuePair<string, string>> list = s.Where(t => true);
        foreach (KeyValuePair<string, string> t in list)
        {
            Console.WriteLine(t.Key + " ---> " + t.Value);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string>() { "1","12","123","1234","a","ab","abc"};
        var lookup=list.ToLookup(x => x.Length);//根据元素的长度分组
        foreach (var t in lookup)
        {
            List<string> temp=t.ToList<string>();//把一组数据转换成集合
            temp.ForEach(x=>Console.Write(x+"、"));//输出集合
            Console.WriteLine();
        }
        Console.Read();
    }
}