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  1. using static System.Console;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4.  
  5. class Program
  6. {
  7.     static void Main()
  8.     {
  9.         string[] input = {
  10.             "a1=a2", "b1=b2", "b3=b2", "c1=c2", "e1=e2", "a3=a4", "c3=c4", "e1=e3",
  11.             "a2=a4", "c3=c1", "b3=a4", "c2=d1", "a4=a5", "d2=c1", "b4=b3", "d3=c3"
  12.         };
  13.  
  14.         var h = new Dictionary<string, int>();
  15.  
  16.         foreach (var e in input.Select(s => s.Split('='))) {
  17.             var (l, r) = (e[0], e[1]);
  18.             switch (h.ContainsKey(l), h.ContainsKey(r)) {
  19.                 case (false, false):
  20.                     h[r] = h[l] = h.Count;
  21.                     break;
  22.                 case (true, false):
  23.                     h[r] = h[l];
  24.                     break;
  25.                 case (false, true):
  26.                     h[l] = h[r];
  27.                     break;
  28.                 case (true, true):
  29.                     h.Where(x => x.Value == h[r]).ToList().ForEach(x => h[x.Key] = h[l]);
  30.                     break;
  31.             }
  32.         }
  33.  
  34.         foreach (var g in h.GroupBy(x => x.Value, x => x.Key)) WriteLine($"[{string.Join(", ", g)}]");
  35.     }
  36. }
Success #stdin #stdout 0.05s 28384KB
comments (?)
stdin 
Standard input is empty
stdout 
[a1, a2, b1, b2, b3, a3, a4, a5, b4]
[c1, c2, c3, c4, d1, d2, d3]
[e1, e2, e3]
https://ideone.com/fvtgZa
language:
C# (NET 6.0)
created:
104 days ago
visibility:
secret

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