Combination Generator

using System;

using CH.Combinations;

namespace CH.Combinations.Benchmark {
	internal class Program {
		private static int _Seconds = 2;

		private static void DoBenchmarkEnumerator<T>(Combinations<T> combs) {
			int count = 0;
			DateTime start = DateTime.UtcNow;
			TimeSpan elapsed;
			do {
				foreach (T[] t in combs) {
					count++;
					if (count % 10000 == 0) {
						elapsed = DateTime.UtcNow - start;
						if (elapsed.Ticks >= _Seconds * TimeSpan.TicksPerSecond) {
							break;
						}
					}
				}
				elapsed = DateTime.UtcNow - start;
			} while (elapsed.Ticks < _Seconds * TimeSpan.TicksPerSecond);
			double eps = ((double) count) / (elapsed.Seconds * 1000 + elapsed.Milliseconds) * 1000.0;
			Console.WriteLine("{0:#,0} e in {1:0.000}s = {2:#,0} e/s", count, elapsed.Seconds + elapsed.Milliseconds / 1000.0, (int) eps);
		}

		private static void DoBenchmarkEnumerator(int n, int r, int percentChanceDuplicate) {
			int[] data = new int[n];
			Random rand = new Random();
			for (int i = 0; i < data.Length; i++) {
				if (rand.Next(100) < percentChanceDuplicate && i > 0) {
					data[i] = data[i - 1];
				} else {
					data[i] = i;
				}
			}
			Combinations<int> combs = new Combinations<int>(data, r);
			DoBenchmarkEnumerator(combs);
		}

		private static void Shuffle<T>(T[] data) {
			int n = data.Length;
			Random r = new Random();
			while (n > 1) {
				int idx = r.Next(n--);
				T temp = data[n];
				data[n] = data[idx];
				data[idx] = temp;
			}
		}

		private enum DatasetBenchmarkType {
			Sequential, Random
		}

		private static void DoBenchmarkDataset(int n, DatasetBenchmarkType type) {
			int[] data = new int[n];
			for (int i = 0; i < data.Length; i++) {
				data[i] = i;
			}
			if (type == DatasetBenchmarkType.Random) {
				Shuffle(data);
			}
			int count = 0;
			DateTime start = DateTime.UtcNow;
			TimeSpan elapsed;
			do {
				new ElementSet<int>(data);
				count++;
				elapsed = DateTime.UtcNow - start;
			} while (elapsed.Ticks < _Seconds * TimeSpan.TicksPerSecond);
			double dsps = ((double) count) / (elapsed.Seconds * 1000 + elapsed.Milliseconds) * 1000.0;
			Console.WriteLine("{0:#,0} ds in {1:0.000}s = {2:#,0} ds/s = {3:#,0} e/s", count, elapsed.Seconds + elapsed.Milliseconds / 1000.0, (int) dsps, (int) (dsps * n));
		}

		private static void Main(string[] args) {
			if (args.Length == 1) {
				_Seconds = int.Parse(args[0]);
			}
			Console.WriteLine("Integer enumerator benchmarks (distinct):");
			Console.Write("10C5 integers:\t\t");
			DoBenchmarkEnumerator(10, 5, 0);
			Console.Write("10C7 integers:\t\t");
			DoBenchmarkEnumerator(10, 7, 0);
			Console.Write("10C3 integers:\t\t");
			DoBenchmarkEnumerator(10, 3, 0);
			Console.Write("100C50 integers:\t");
			DoBenchmarkEnumerator(100, 50, 0);
			Console.Write("100C70 integers:\t");
			DoBenchmarkEnumerator(100, 70, 0);
			Console.Write("100C30 integers:\t");
			DoBenchmarkEnumerator(100, 30, 0);
			Console.Write("1000C500 integers:\t");
			DoBenchmarkEnumerator(1000, 500, 0);
			Console.Write("1000C700 integers:\t");
			DoBenchmarkEnumerator(1000, 700, 0);
			Console.Write("1000C300 integers:\t");
			DoBenchmarkEnumerator(1000, 300, 0);

			Console.WriteLine();
			Console.WriteLine("Integer enumerator benchmarks (10% duplicates):");
			Console.Write("10C5 integers:\t\t");
			DoBenchmarkEnumerator(10, 5, 10);
			Console.Write("10C7 integers:\t\t");
			DoBenchmarkEnumerator(10, 7, 10);
			Console.Write("10C3 integers:\t\t");
			DoBenchmarkEnumerator(10, 3, 10);
			Console.Write("100C50 integers:\t");
			DoBenchmarkEnumerator(100, 50, 10);
			Console.Write("100C70 integers:\t");
			DoBenchmarkEnumerator(100, 70, 10);
			Console.Write("100C30 integers:\t");
			DoBenchmarkEnumerator(100, 30, 10);
			Console.Write("1000C500 integers:\t");
			DoBenchmarkEnumerator(1000, 500, 10);
			Console.Write("1000C700 integers:\t");
			DoBenchmarkEnumerator(1000, 700, 10);
			Console.Write("1000C300 integers:\t");
			DoBenchmarkEnumerator(1000, 300, 10);

			Console.WriteLine();
			Console.WriteLine("Integer enumerator benchmarks (25% duplicates):");
			Console.Write("10C5 integers:\t\t");
			DoBenchmarkEnumerator(10, 5, 25);
			Console.Write("10C7 integers:\t\t");
			DoBenchmarkEnumerator(10, 7, 25);
			Console.Write("10C3 integers:\t\t");
			DoBenchmarkEnumerator(10, 3, 25);
			Console.Write("100C50 integers:\t");
			DoBenchmarkEnumerator(100, 50, 25);
			Console.Write("100C70 integers:\t");
			DoBenchmarkEnumerator(100, 70, 25);
			Console.Write("100C30 integers:\t");
			DoBenchmarkEnumerator(100, 30, 25);
			Console.Write("1000C500 integers:\t");
			DoBenchmarkEnumerator(1000, 500, 25);
			Console.Write("1000C700 integers:\t");
			DoBenchmarkEnumerator(1000, 700, 25);
			Console.Write("1000C300 integers:\t");
			DoBenchmarkEnumerator(1000, 300, 25);

			Console.WriteLine();
			Console.WriteLine("Integer enumerator benchmarks (60% duplicates):");
			Console.Write("10C5 integers:\t\t");
			DoBenchmarkEnumerator(10, 5, 60);
			Console.Write("10C7 integers:\t\t");
			DoBenchmarkEnumerator(10, 7, 60);
			Console.Write("10C3 integers:\t\t");
			DoBenchmarkEnumerator(10, 3, 60);
			Console.Write("100C50 integers:\t");
			DoBenchmarkEnumerator(100, 50, 60);
			Console.Write("100C70 integers:\t");
			DoBenchmarkEnumerator(100, 70, 60);
			Console.Write("100C30 integers:\t");
			DoBenchmarkEnumerator(100, 30, 60);
			Console.Write("1000C500 integers:\t");
			DoBenchmarkEnumerator(1000, 500, 60);
			Console.Write("1000C700 integers:\t");
			DoBenchmarkEnumerator(1000, 700, 60);
			Console.Write("1000C300 integers:\t");
			DoBenchmarkEnumerator(1000, 300, 60);

			Console.WriteLine();
			Console.WriteLine("Integer dataset preparation benchmarks (sequential):");
			Console.Write("10 integers:\t");
			DoBenchmarkDataset(10, DatasetBenchmarkType.Sequential);
			Console.Write("100 integers:\t");
			DoBenchmarkDataset(100, DatasetBenchmarkType.Sequential);
			Console.Write("1000 integers:\t");
			DoBenchmarkDataset(1000, DatasetBenchmarkType.Sequential);
			Console.Write("10000 integers:\t");
			DoBenchmarkDataset(10000, DatasetBenchmarkType.Sequential);

			Console.WriteLine();
			Console.WriteLine("Integer dataset preparation benchmarks (random):");
			Console.Write("10 integers:\t");
			DoBenchmarkDataset(10, DatasetBenchmarkType.Random);
			Console.Write("100 integers:\t");
			DoBenchmarkDataset(100, DatasetBenchmarkType.Random);
			Console.Write("1000 integers:\t");
			DoBenchmarkDataset(1000, DatasetBenchmarkType.Random);
			Console.Write("10000 integers:\t");
			DoBenchmarkDataset(10000, DatasetBenchmarkType.Random);
		}
	}
}