using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace hashChain
{
    public partial class Form1 : Form
    {
        public struct NumberListData
        {
            public int Data;
            public int Pointer;
        }
        public const int AREASIZE = 50;
        public const int HASHSIZE = 16;
        public int ErasePointer;
        public static NumberListData[] NumberList = new NumberListData[AREASIZE];
        public int[] Bucket = new int[HASHSIZE];
        
        public void BucketInitialize()
        {
            for (int i = 0; i < Bucket.Length; i++) Bucket[i] = -1;
        }
        public void AreaInitialize()
        {
            int i;
            for (i = 0; i < NumberList.Length; i++) NumberList[i].Pointer = i + 1;
            NumberList[NumberList.Length - 1].Pointer = -1;
            ErasePointer = 0;
        }
        public int GetArea()
        {
            if (ErasePointer < 0) return -1;
            int P = ErasePointer;
            ErasePointer = NumberList[ErasePointer].Pointer;
            return P;
        }
        public void FreeArea(int P)
        {
            NumberList[P].Pointer = ErasePointer;
            ErasePointer = P;
        }
        public int replaca(int P, int A)
        {
            NumberList[P].Data = A;
            return P;
        }
        public int replacd(int P, int A)
        {
            NumberList[P].Pointer = A;
            return A;
        }
        public int car(int P)
        {
            return NumberList[P].Data;
        }
        public int cdr(int P)
        {
            return NumberList[P].Pointer;
        }
        public int cons(int A, int B)
        {
            int P = GetArea();
            if (P < 0) return -1;
            NumberList[P].Data = A;
            NumberList[P].Pointer = B;
            return P;
        }
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, System.EventArgs e)
        {
            BucketInitialize();
            AreaInitialize();
            ポインタ部の表示();
        }

        private void ポインタ部の表示()
        {
            listBox1.Items.Clear();
            listBox1.Items.Add("Erase Pointer=" + ErasePointer.ToString());
            listBox1.Items.Add("(ポインタ部のみ)");

            int i = ErasePointer;
            while (i >= 0)
            {
                i = cdr(i);
                listBox1.Items.Add(i.ToString());
            }
        }

        private void button1_Click(object sender, System.EventArgs e)
        {

            int P = GetArea();
            string PS = P.ToString(); textBox1.Text = PS;
            ポインタ部の表示();
            MessageBox.Show(PS);
        }
        private void button2_Click(object sender, System.EventArgs e)
        {
            FreeArea(int.Parse(textBox1.Text));
            ポインタ部の表示();
        }
        private void ハッシュ表示()
        {
            string S; int P;
            listBox1.Items.Clear();
            for (int i = 0; i < Bucket.Length; i++)
            {
                S = i.ToString() + " "; P = Bucket[i];
                if (P >= 0)
                {
                    while (P >= 0)
                    {
                        S += " " + car(P).ToString();
                        P = cdr(P);
                    }
                    listBox1.Items.Add(S);
                }
                else listBox1.Items.Add(S + "(空)");
            }
        }

        private int SearchKey(int Key, int P)
        {
            int PP = P;
            while (PP >= 0)
            {
                if (car(PP) == Key) return PP;
                PP = cdr(PP);
            }
            return -1;
        }
        private void ハッシュ設定(int Key, int Mod)
        {
            int ID = Key % Mod;
            if (SearchKey(Key, Bucket[ID]) < 0) Bucket[ID] = cons(Key, Bucket[ID]);

        }
        private void button3_Click(object sender, System.EventArgs e)
        {
            int Mod = Bucket.Length;
            int Key = int.Parse(textBox1.Text);
            ハッシュ設定(Key, Mod);
            ハッシュ表示();
        }


        private int ハッシュ探索(int Key, int Mod)
        {
            int ID = Key % Mod;
            return SearchKey(Key, Bucket[ID]);
        }

        private void button4_Click(object sender, System.EventArgs e)
        {
            int Mod = Bucket.Length;
            int Key = int.Parse(textBox1.Text);
            int P = ハッシュ探索(Key, Mod);
            MessageBox.Show(P.ToString());
        }

        private int ハッシュ削除(int Key, int Mod)
        {
            int ID = Key % Mod;
            int Befor = -1;
            int P = Bucket[ID];
            if (P < 0) return -1;
            while (P >= 0)
            {
                if (car(P) == Key) break;
                Befor = P;
                P = cdr(P);
            }
            int After = cdr(P); FreeArea(P);
            if (Befor < 0) Bucket[ID] = After;
            else replacd(Befor, After);
            return After;
        }

        private void button5_Click(object sender, System.EventArgs e)
        {
            int Mod = Bucket.Length;
            int Key = int.Parse(textBox1.Text);
            int P = ハッシュ削除(Key, Mod);
            ハッシュ表示();
        }
    }
}