c#字符串中统计字符出现次数并排序。

[名称名称]

stinrg bb="ABCDEFGHIJ";
string aa = "ABCAAABBCBHHHHBAEEEHAABJBCCABCAEFGHIJGHIJJJJI";
bb中的每个字符aa中的重复的重复次数如下：
A-9次 E-4次 I-3次
B-8次 F-1次 J-6次
C-5次 G-2次
D-0次 H-7次

怎么才能获取string cc=
结果是：ABHJCEIGFD
string cc=ABHJCEIGFD 怎么才能获取这个结果？

也就是说cc是bb中的每个字符aa中出现次数最大的放最左边，大到小排序后出来结果。就是统计出现次数来排序。

[MYsce]

引用 4 楼 xuzuning 的回复:

            string bb = "ABCDEFGHIJ";
            string aa = "ABCAAABBCBHHHHBAEEEHAABJBCCABCAEFGHIJGHIJJJJI";
            var r = bb.SelectMany(x=> aa.Where(y => x==y)).GroupBy(x =>x).OrderByDescending(x=>x.Count());
            var cc = string.Join("", r.Select(x => x.Key));
            Console.WriteLine(cc);

好像少了个d

[MYsce]

string aa = "ABCAAABBCBHHHHBAEEEHAABJBCCABCAEFGHIJGHIJJJJI";
             string bb = "ABCDEFGHIJ";
             var t = aa.GroupBy(g => g).Select(s => new { k = s.Key, c = s.Count() }).OrderByDescending(o => o.c).Select(s1 => s1.k).Where(w => bb.Select(s => s).ToList().Contains(w)).Union(bb);
            string cc = string.Join("", t);
            Console.WriteLine(cc);

[xdashewan]

参考http://www.cnblogs.com/YuanSong/archive/2012/10/16/2725956.html

[易2017]

引用 1 楼 xdashewan 的回复:

参考http://www.cnblogs.com/YuanSong/archive/2012/10/16/2725956.html

学习

[by_封爱]

string bb = "ABCDEFGHIJ";
string aa = "ABCAAABBCBHHHHBAEEEHAABJBCCABCAEFGHIJGHIJJJJI";

var qs = aa.GroupBy(d => d).
   Where(d => bb.Contains(d.Key)).
   Select(d => new { k = d.Key.ToString(), c = d.Count() }).
   OrderByDescending(d => d.c).
   Select(d => d.k).ToArray();

string cc = string.Join("", qs);

Response.Write(cc);

引用

ABHJCEIGF

[xuzuning]

            string bb = "ABCDEFGHIJ";
            string aa = "ABCAAABBCBHHHHBAEEEHAABJBCCABCAEFGHIJGHIJJJJI";
            var r = bb.SelectMany(x=> aa.Where(y => x==y)).GroupBy(x =>x).OrderByDescending(x=>x.Count());
            var cc = string.Join("", r.Select(x => x.Key));
            Console.WriteLine(cc);

[橘子皮...]

 string bb = "ABC";
            string aa = "AABBBCCCC";
            ConcurrentDictionary<string, int> cd = new ConcurrentDictionary<string, int>();

            Parallel.For(0,aa.Length , i => {
                var s = aa.Substring(i, 1);
                cd.AddOrUpdate(s, 1, (key, value) => {
                    return value += 1;
                });
            });

写了一半，下面想不出来怎么写好了

[大葡萄八块一斤]

            var cc = bb.Select(x => x).GroupJoin(aa.GroupBy(y => y).Select(x => new { aKey = x.Key, aCount = x.Count() }),
                b => b, f => f.aKey,
                (b, grp) => new { b = b, grp = grp })
                .SelectMany(temp => temp.grp.DefaultIfEmpty(),
               (temp, grp) =>
                  new
                  {
                      str = temp.b,
                      i = (grp == null) ? 0 : grp.aCount
                  }).OrderByDescending(x => x.i).Select(x => x.str.ToString());


            string result = string.Join("", cc.ToArray());