Created
June 29, 2015 10:32
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using System.Collections.Generic; | |
using System.Linq; | |
namespace MergeLinks | |
{ | |
public class Disjoint<T> | |
{ | |
private readonly Dictionary<int, HashSet<T>> _groups; | |
private int _lastGroupKey = 0; | |
public Disjoint() | |
{ | |
_groups = new Dictionary<int, HashSet<T>>(); | |
} | |
public IEnumerable<IEnumerable<T>> Groups | |
{ | |
get { | |
return _groups.Select(@group => @group.Value); | |
} | |
} | |
public void Add(T a, T b) | |
{ | |
var aRoot = Find(a); | |
var bRoot = Find(b); | |
if (aRoot.HasValue && !bRoot.HasValue) | |
{ | |
AddToExisting(b, aRoot.Value); | |
} | |
else if (!aRoot.HasValue && bRoot.HasValue) | |
{ | |
AddToExisting(a, bRoot.Value); | |
} | |
else if (aRoot.HasValue && bRoot.HasValue && aRoot.Value != bRoot.Value) | |
{ | |
Union(aRoot.Value, bRoot.Value); | |
} | |
else if (!aRoot.HasValue && !bRoot.HasValue) | |
{ | |
var @new = AddToNew(a); | |
AddToExisting(b, @new); | |
} | |
else /* aRoot.Value == bRoot.Value */ | |
{ | |
// Do nothing! | |
} | |
} | |
private void Union(int aRoot, int bRoot) | |
{ | |
foreach (var elem in _groups[bRoot]) | |
{ | |
_groups[aRoot].Add(elem); | |
} | |
_groups.Remove(bRoot); | |
} | |
private void AddToExisting(T b, int parent) | |
{ | |
_groups[parent].Add(b); | |
} | |
private int AddToNew(T b) | |
{ | |
var newGroupKey = _lastGroupKey; | |
_groups.Add(newGroupKey, new HashSet<T>() { b }); | |
_lastGroupKey = newGroupKey + 1; | |
return newGroupKey; | |
} | |
public int? Find(T elem) | |
{ | |
foreach (var @group in _groups.Where(@group => @group.Value.Contains(elem))) | |
{ | |
return @group.Key; | |
} | |
return null; | |
} | |
} | |
} |
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using System.IO; | |
using System.Linq; | |
namespace MergeLinks | |
{ | |
class Program | |
{ | |
static void Main(string[] args) | |
{ | |
var ds = new Disjoint<int>(); | |
using (var tr = File.OpenText(args[0])) | |
{ | |
int progress = 0; | |
while (!tr.EndOfStream) | |
{ | |
var line = tr.ReadLine(); | |
var segments = line.Split('\t').Select(int.Parse).ToList(); | |
ds.Add(segments[0], segments[1]); | |
Console.Write("\r{0}", progress++); | |
} | |
} | |
int num = 1; | |
foreach (var @group in ds.Groups) | |
{ | |
Console.WriteLine("{0}. {1}", num++, string.Join(",", @group)); | |
} | |
Console.ReadKey(); | |
} | |
} | |
} |
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