"有道难题"之ealget的改进算法~

夜的咖啡 的算法 839毫秒

eaglet 的算法 1919毫秒

原帖：http://www.cnblogs.com/eaglet/archive/2009/06/01/1493801.html

刚刚学C#……算法也没怎么去看……就凭着自己的想法写了……代码看起来很简单哈

 

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
namespace ConsoleEx
{
    public class Run
    {
        public static void Main()
        {
            Stopwatch sw = new Stopwatch();

            string[] testField = {
                "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890",
                 "1234567890"};

            //夜的咖啡 的算法
            Console.WriteLine("夜的咖啡 的算法");
            Console.WriteLine(T2.countSpecialNumbers(new string[] { "111", "111", "111" }, 4, 8));
            Console.WriteLine(T2.countSpecialNumbers(new string[] { "111", "141", "111" }, 4, 8));
            Console.WriteLine(T2.countSpecialNumbers(new string[] { "2309", "0239", "2314" }, 5, 7));
            Console.WriteLine(T2.countSpecialNumbers(new string[] { "924", "231", "390", "910", "121" }, 31, 36));
            Console.WriteLine(T2.countSpecialNumbers(new string[] { "5" }, 3, 8));
            Console.WriteLine(T2.countSpecialNumbers(testField, 3, 18));


            sw.Start();
            for (int i = 0; i < 100000; i++)
            {
                T2.countSpecialNumbers(testField, 3, 18);
            }

            sw.Stop();

            Console.WriteLine("用时" + sw.ElapsedMilliseconds.ToString() + "毫秒");

            Console.WriteLine("eaglet 的算法");

            Console.WriteLine(T1.countSpecialNumbers(new string[] { "111", "111", "111" }, 4, 8));
            Console.WriteLine(T1.countSpecialNumbers(new string[] { "111", "141", "111" }, 4, 8));
            Console.WriteLine(T1.countSpecialNumbers(new string[] { "2309", "0239", "2314" }, 5, 7));
            Console.WriteLine(T1.countSpecialNumbers(new string[] { "924", "231", "390", "910", "121" }, 31, 36));
            Console.WriteLine(T1.countSpecialNumbers(new string[] { "5" }, 3, 8));
            Console.WriteLine(T1.countSpecialNumbers(testField, 3, 18));

            sw.Reset();
            sw.Start();


            for (int i = 0; i < 100000; i++)
            {
                T1.countSpecialNumbers(testField, 3, 18);
            }

            sw.Stop();

            Console.WriteLine("用时" + sw.ElapsedMilliseconds.ToString() + "毫秒");


            Console.ReadKey();
        }


        class T2
        {
            /**/
            /// <summary>
            /// 获取第i,j格的特殊程度
            /// </summary>
            /// <param name="field"></param>
            /// <param name="i"></param>
            /// <param name="j"></param>
            /// <returns></returns>
            /// <author>NightCoffee</author>
            static private int GetSpecialNumbers(string[] field, int width, int i, int j)
            {
                
                int sum = 0;
                if (i - 1 >= 0)//上面有格子
                {
                    sum += field[i-1][j] - '0';
                    if (j - 1 >= 0)
                    {
                        sum += field[i - 1][j-1] - '0';
                    }
                    if (j + 1 <= width - 1)
                    {
                        sum += field[i - 1][j+1] - '0';
                    }
                }
                if (i + 1 <= field.Length - 1) //下面有格子
                {
                    sum += field[i+1][j] - '0';
                    if (j - 1 >= 0)
                    {
                        sum += field[i + 1][j - 1] - '0';
                    }
                    if (j + 1 <= width - 1)
                    {
                        sum += field[i + 1][j + 1] - '0';
                    }
                }
                if (j - 1 >= 0) //左边有格子
                {
                    sum += field[i][j - 1] - '0';
                }
                if (j + 1 <= width - 1) //右边有格子
                {
                    sum += field[i][j + 1] - '0';
                }
                return sum;
            }

            /**/
            /// <summary>
            /// 
            /// </summary>
            /// <param name="field"></param>
            /// <param name="A"></param>
            /// <param name="B"></param>
            /// <returns></returns>
            /// <author>NightCoffee Base on eaglet</author>
            static public int countSpecialNumbers(string[] field, int A, int B)
            {
                //Check paramaters
                if (field == null)
                {
                    return 0;
                }

                if (field.Length == 0)
                {
                    return 0;
                }

                int width = field[0].Length;

                if (width == 0)
                {
                    return 0;
                }

                if (A > B)
                {
                    throw new ArgumentException("A > B");
                }

                //Begin calculate
                int count = 0;

                for (int i = 0; i < field.Length; i++)
                {
                    for (int j = 0; j < field[i].Length; j++)
                    {
                        int number = GetSpecialNumbers(field, width, i, j);

                        if (number >= A && number <= B)
                        {
                            count++;
                        }
                    }
                }

                return count;
            }
        }
        class T1
        {
            /**/
            /// <summary>
            /// 获取第i,j格的特殊程度
            /// </summary>
            /// <param name="field"></param>
            /// <param name="i"></param>
            /// <param name="j"></param>
            /// <returns></returns>
            /// <author>eaglet</author>
            static private int GetSpecialNumbers(string[] field, int width, int i, int j)
            {
                int y = i - 1 >= 0 ? i - 1 : 0;
                int sum = 0;

                while (y <= i + 1 && y < field.Length)
                {
                    int x = j - 1 >= 0 ? j - 1 : 0;

                    while (x <= j + 1 && x < width)
                    {
                        if (x != j || y != i)
                        {
                            sum += field[y][x] - '0';
                        }

                        x++;
                    }

                    y++;
                }

                return sum;
            }

            /**/
            /// <summary>
            /// 
            /// </summary>
            /// <param name="field"></param>
            /// <param name="A"></param>
            /// <param name="B"></param>
            /// <returns></returns>
            /// <author>eaglet</author>
            static public int countSpecialNumbers(string[] field, int A, int B)
            {
                //Check paramaters
                if (field == null)
                {
                    return 0;
                }

                if (field.Length == 0)
                {
                    return 0;
                }

                int width = field[0].Length;

                if (width == 0)
                {
                    return 0;
                }

                if (A > B)
                {
                    throw new ArgumentException("A > B");
                }

                //Begin calculate
                int count = 0;

                for (int i = 0; i < field.Length; i++)
                {
                    for (int j = 0; j < field[i].Length; j++)
                    {
                        int number = GetSpecialNumbers(field, width, i, j);

                        if (number >= A && number <= B)
                        {
                            count++;
                        }
                    }
                }

                return count;
            }
        }
    }

}