C#练习题答案: 老switcheroo 2【难度：1级】--景越C#经典编程题库,1000道C#基础练习题等你来挑战

老switcheroo 2【难度:1级】:

答案1:

using System;
using System.Linq;
public class Kata {
  public static string Encode(string str) {
    string alpha = "_abcdefghijklmnopqrstuvwxyz";
    return String.Concat(str.ToLower().Select((c, i) => Char.IsLetter(c) ? "" + (alpha.IndexOf(c)) : "" + c));
  }
}​

答案2:

using System.Text.RegularExpressions;
public class Kata
{
  public static string Encode(string str)
  {
    return Regex.Replace(str,"[a-zA-Z]",s=>str[s.Index]-(str[s.Index]>96 ? 96 : 64)+"");
  }
}​

答案3:

using System;
using System.Collections.Generic;
public class Kata
{
  public static string Encode(string str)
  {
    string ret = string.Empty;
    foreach(char chr in str)
    {
      ret += Char.IsLetter(chr) ? ((int)chr % 32).ToString() : chr.ToString();
    }
    return ret;
  }
}​

答案4:

using System;

public class Kata
{
  public static string Encode(string str)
  {
     string res = "";
            foreach(char c in str)
            {
                if(char.IsLetter(c) && !char.IsLower(c)) { res+= c - 64; }
                else if (char.IsLetter(c) && char.IsLower(c)) { res+= c - 96; }
                else { res+= c;}
            }
            return res;
  }
}​

答案5:

using System;
using System.Text;

public class Kata
{
  public static string Encode(string str)
  {
            StringBuilder sb = new StringBuilder();

            str = str.ToLower();

            for (int i = 0; i < str.Length; i++)
            {
                if (Char.IsLetter(str[i]))
                {
                    string p = (str[i] - 96).ToString();
                    sb.Append(p);
                }
                else
                    sb.Append(str[i]);
            }

            return sb.ToString();
  }
}​

答案6:

using System;
using System.Collections.Generic;

public class Kata
{
    public static string Encode(string str)
    {

        Dictionary<string, int> dictionary = new Dictionary<string, int>
        {
            {"a",1 },
            {"b",2 },
            {"c",3 },
            {"d",4 },
            {"e",5 },
            {"f",6 },
            {"g",7 },
            {"h",8 },
            {"i",9 },
            {"j",10 },
            {"k",11},
            {"l",12 },
            {"m",13 },
            {"n",14 },
            {"o",15 },
            {"p",16 },
            {"q",17 },
            {"r",18},
            {"s",19 },
            {"t",20 },
            {"u",21 },
            {"v",22 },
            {"w",23 },
            {"x",24 },
            {"y",25 },
            {"z",26 },
        };

        var result = "";

        foreach (var val in str.ToLower())
        {
            if (char.IsLetter(val))
            {
                result += dictionary[val.ToString()];
            }
            else
            {
                result += val;
            }
        }

        return result;
    }
}​

答案7:

using System;

public class Kata
{
  public static string Encode(string str)
  {
    string strResult = string.Empty;
    foreach(char c in str)
    {
      if (c >= 'a' &amp;&amp; c <= 'z')
        strResult += (c - 'a' + 1).ToString();
      else if (c >= 'A' &amp;&amp; c <= 'Z')
        strResult += (c - 'A' + 1).ToString();
      else
        strResult += c.ToString();
    }
return strResult;
  }
}​

答案8:

using System;
using System.Linq;

public class Kata
{
  public static string Encode(string cc)
  {
    return string.Join(string.Empty,
                cc.Select(ch => char.IsLetter(ch) ? ((ch - (Char.IsLower(ch) ? 'a' : 'A')) + 1).ToString() : ch.ToString()).ToArray());
  }
}​

答案9:

using System.Text.RegularExpressions;

public class Kata
{
  public static string Encode(string str)
  {
    return Regex.Replace(str.ToLower(), "[a-z]", m => ((int)char.Parse(m.Value) - 96).ToString());
  }
}​

答案10:

using System;
using System.Linq;

public class Kata
{
        public static string Encode(string str)
        {
            return string.Concat(str.Select(ch =>
            {
                if (char.IsLetter(ch))
                {
                    ch = (char)((int)ch | 0x0020);
                    return ((int)ch - 96).ToString();
                }
                return ch.ToString();
            }));
        }  
  
}​