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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        List<MyData> data = new List<MyData>();
        List<MyData> data0 = new List<MyData>();
        List<MyData> data1 = new List<MyData>();
        List<MyData> data2 = new List<MyData>();
        Button b;
        private void Form1_Load(object sender, EventArgs e)
        {
            data.Clear();
            data0.Clear();
            data1.Clear();
            data2.Clear();
            for (int i = 0; i < 30000; i++)
            {
                MyData d = new MyData();
                d.hogehoe = i;
                data.Add(d);
                if (i < 10000)
                {
                    data0.Add(d);
                }
                else if (i < 20000)
                {
                    data1.Add(d);
                }
                else
                {
                    data2.Add(d);
                }
            }
            b = new Button();
            b.Text = "実行";
            b.Click += new EventHandler(b_Click);
            this.Controls.Add(b);
        }

        void b_Click(object sender, EventArgs e)
        {
            b.Enabled = false;
            int i = 29999;
            MyData aheahe;
            if (i < 10000)
            {
                aheahe = this.datafind(data0, i);
            }
            else if (i < 20000)
            {
                aheahe = this.datafind(data1, i);
            }
            else
            {
                aheahe = this.datafind(data2, i);
            }
            if (aheahe != null) this.Text = aheahe.hogehoe.ToString();
            b.Enabled = true;
        }
        MyData datafind(List<MyData> kkkkkkkk, int number)
        {
            MyData mmmm = null;
            foreach (MyData md in kkkkkkkk)
            {
                if (md.hogehoe == number)
                {
                    mmmm = md;
                    break;
                }
            }
            return mmmm;
        }
    }
    public class MyData
    {
        public int hogehoe;
    }
}