题解 | #字符串排序#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class Program {
    public static void Main() {
        string line;
        while ((line = System.Console.ReadLine ()) != null) { // 注意 while 处理多个 case
            OnFunc1(line);
        }
    }
    public static void OnFunc1(string line)
    {
        var arr=line.Where(C=>char.IsLetter(C)).ToArray();
        List<char> letter=new List<char>();
        for(int j=0;j<26;j++)
        {
            for(int i=0;i<arr.Length;i++)
            {
                if(arr[i]-'a'==j || arr[i]-'A'==j)
                {
                    letter.Add(arr[i]);
                }
            }
        }
        //Console.WriteLine(string.Join("", letter));
        StringBuilder sb=new StringBuilder();
        int index=0;
        foreach(char item in line)
        {
            if(char.IsLetter(item))
            {
                sb.Append(letter[index++]);
            }
            else
            {
                sb.Append(item.ToString());
            }
        }
        Console.WriteLine(sb.ToString());
    }
}