线性表顺序存储结构的方法

顺序存储
1.顺序表的优点：读取元素时可直接定位，
所以在某些操作(比如将顺序表元素反转合围)中，不需要完全遍历，
循环次数(即时间复杂度)相对完全遍历而言能减少一半。
2.顺序表的缺点：插入/删除元素，因为要保持其顺序性，所以后续元素需要移动，
增加了时间开销。
SeqListDemo
1、主函数中的各项输出

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SeqListDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            SeqList<string> seq = new SeqList<string>(10);
            seq.Append("x");
            seq.InsertBefore("w", 0);
            seq.InsertBefore("v", 0);
            seq.Append("y");
            seq.InsertBefore("z", seq.Count());
            Console.WriteLine(seq.Count());//5
            Console.WriteLine(seq);//v,w,x,y,z
            Console.WriteLine(seq[1]);//w
            Console.WriteLine(seq[0]);//v
            Console.WriteLine(seq[4]);//z
            Console.WriteLine(seq.IndexOf("a"));//4
            Console.WriteLine(seq.RemoveAt(2));//x
            Console.WriteLine(seq);//v,w,y,z
            seq.InsertBefore("x", 2);
            Console.WriteLine(seq);//v,w,x,y,z
            Console.WriteLine(seq.GetItemAt(2));//x
            seq.Reverse();
            Console.WriteLine(seq);//z,y,x,w,v
            seq.InsertAfter("z_1", 0);
            seq.InsertAfter("y_1", 2);
            seq.InsertAfter("v_1", seq.Count() - 1);
            Console.WriteLine(seq);
            Console.ReadKey();
        }
    }
}

2、顺序结构中的方法：
SeqList.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SeqListDemo
{
    /// <summary>
    /// 顺序存储
    /// </summary>
    /// <typeparam name="T"></typeparam>
    class SeqList<T> : ISepList<T>
    {
        private int maxsize;
        private T[] data;
        private int last;
        //类索引器
        public T this[int index]
        {
            get
            {
                return GetItemAt(index);
            }
            set
            {
                if (index < 0 || index > last + 1)
                {
                    Console.WriteLine("Position is error");
                    return;
                }
                data[index] = value;
            }
        }
        //最后一个元素的下标
        public int Last
        {
            get { return last; }
        }
        //最大容量
        public int Maxsize
        {
            get { return maxsize; }
            set { maxsize = value; }
        }
        //构造函数
        public SeqList(int size)
        {
            data = new T[size];
            maxsize = size;
            last = -1;
        }
        public void Append(T item)
        {
            if (IsFull())
            {
                Console.WriteLine("List is full");
                return;
            }
            data[++last] = item;
        }

        public void Clear()
        {
            last = -1;
        }

        public int Count()
        {
            return last + 1;
        }
        /// <summary>
        /// 获取第i个位置的元素
        /// </summary>
        /// <param name="i"></param>
        /// <returns></returns>
        public T GetItemAt(int i)
        {
            if (IsEmpty() || (i < 0) || (i > last))
            {
                Console.WriteLine("List is empty or Position is error!");
                return default(T);
            }
            return data[i];
        }
        /// <summary>
        /// 定位元素的下标索引
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public int IndexOf(T value)
        {
            if (IsEmpty())
            {
                Console.WriteLine("List is Empty!");
                return -1;
            }
            int i = 0;
            for (i = 0; i <= last; i++)
            {
                if (value.Equals(data[i]))
                {
                    break;
                }
                if (i==last&&!value.Equals(data[i]))
                {
                    Console.WriteLine("所查元素不在表中");
                    return -1;
                }
            }
            if (i > last)
            {
                return -1;
            }
            return i;
        }
        /// <summary>
        /// 后插
        /// </summary>
        /// <param name="item"></param>
        /// <param name="i"></param>
        public void InsertAfter(T item, int i)
        {
            if (IsFull())
            {
                Console.WriteLine("List is full");
                return;
            }
            if (i < 0 || i > last)
            {
                Console.WriteLine("Position is error");
                return;
            }
            if (i == last)
            {
                data[last + 1] = item;
            }
            else
            {
                //位置i以后的元素(不含位置i)，全部后移
                for (int j = last; j > i; j--)
                {
                    data[j + 1] = data[j];
                }
                data[i + 1] = item;
            }
            ++last;
        }
        /// <summary>
        /// 前插
        /// </summary>
        /// <param name="item"></param>
        /// <param name="i"></param>
        public void InsertBefore(T item, int i)
        {
            if (IsFull())
            {
                Console.WriteLine("List is full");
                return;
            }
            if (i < 0 || i > last + 1)
            {
                Console.WriteLine("Position is error");
                return;
            }
            if (i == last + 1)
            {
                data[last + 1] = item;
            }
            else
            {
                //位置i及i以后的元素，全部后移
                for (int j = last; j >= i; j--)
                {
                    data[j + 1] = data[j];
                }
                data[i] = item;
            }
            ++last;
        }

        public bool IsEmpty()
        {
            return last == -1;
        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="i"></param>
        /// <returns></returns>
        public T RemoveAt(int i)
        {
            T tmp = default(T);
            if (IsEmpty())
            {
                Console.WriteLine("List is empty");
                return tmp;
            }
            if (i < 0 || i > last)
            {
                Console.WriteLine("Position is error!");
                return tmp;
            }
            if (i == last)
            {
                tmp = data[last];
            }
            else
            {
                tmp = data[i];
                //位置i以及i以后的元素前移
                for (int j = i; j <= last; j++)
                {
                    data[j] = data[j + 1];
                }
            }
            --last;
            return tmp;
        }
        /// <summary>
        /// 元素反转
        /// </summary>
        public void Reverse()
        {
            T tmp = default(T);
            for (int i = 0; i <= last / 2; i++)
            {
                tmp = data[i];
                data[i] = data[last - i];
                data[last - i] = tmp;
            }
        }
        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i <= last; i++)
            {
                sb.Append(data[i].ToString() + "，");
            }
            return sb.ToString().TrimEnd('，');
        }

        public bool IsFull()
        {
            return last == maxsize - 1;
        }
    }
}

3、方法继承的接口
ISepList

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SeqListDemo
{
    interface ISepList<T>
    {
        //取得线性表的实际元素个数
        int Count();
        //清空线性表
        void Clear();
        //判断线性表是否为空
        bool IsEmpty();
        //（在末端）追加元素
        void Append(T item);
        //在位置i“前面”插入元素item
        void InsertBefore(T item, int i);
        //在位置i“后面”插入元素item
        void InsertAfter(T item, int i);
        //删除索引i处的元素
        T RemoveAt(int i);
        //获得索引位置i处的元素
        T GetItemAt(int i);
        //返回元素value的索引
        int IndexOf(T value);
        //反转线性表的所有元素
        void Reverse();
        //是否满了
        bool IsFull();
    }
}