Sets of three common numbers benchmark

Tester.cs

using System;
using System.Diagnostics;
using System.Collections.Generic;

public class Tester {

	public static void Main() {
		var count = 1000000;
		var tris0 = new int[count * 3];
		var tris1 = new int[count * 3];

		var rand = new Random();

		var t0 = new int[3];
		var t1 = new int[3];

		for (int t = 0; t < tris0.Length; t+=3) {
			t0[0] = (int)(rand.NextDouble() * 50);
			t0[1] = (int)(rand.NextDouble() * 50);
			t0[2] = (int)(rand.NextDouble() * 50);

			t1[0] = (int)(rand.NextDouble() * 50);
			t1[1] = (int)(rand.NextDouble() * 50);
			t1[2] = (int)(rand.NextDouble() * 50);

			tris0[t] = t0[0];
			tris0[t+1] = t0[1];
			tris0[t+2] = t0[2];

			tris1[t] = t1[0];
			tris1[t+1] = t1[1];
			tris1[t+2] = t1[2];

			Array.Sort(t0);
			Array.Sort(t1);

			if (t0[0] == t1[0] && t0[1] == t1[1] && t0[2] == t1[2]) {
				// Triangles are identical, try again.
				t -= 3;
				continue;
			}

			if (t0[0] == t0[1] || t0[1] == t0[2]) {
				// Triangle contains repeated value, try again. 
				t -= 3;
				continue;
			}

			if (t1[0] == t1[1] || t1[1] == t1[2]) {
				// Triangle contains repeated value, try again. 
				t -= 3;
				continue;
			}
		}

		var watch = new Stopwatch();

		watch.Start();
		var c1 = SharedEdgeCount1(tris0, tris1);
		watch.Stop();

		var time1 = watch.Elapsed;

		watch.Restart();
		var c2 = SharedEdgeCount2(tris0, tris1);
		watch.Stop();
		
		var time2 = watch.Elapsed;

		watch.Restart();
		var c3 = SharedEdgeCount3(tris0, tris1);
		watch.Stop();

		var time3 = watch.Elapsed;

		watch.Restart();
		var c4 = SharedEdgeCount4(tris0, tris1);
		watch.Stop();

		var time4 = watch.Elapsed;

		watch.Restart();
		var c5 = SharedEdgeCount5(tris0, tris1);
		watch.Stop();

		var time5 = watch.Elapsed;
		
		Console.WriteLine("Original method result: \t" + c1 + ", time elapsed in ms: \t" + time1.TotalMilliseconds);
		Console.WriteLine("qwertyman method result: \t" + c2 + ", time elapsed in ms: \t" + time2.TotalMilliseconds);
		Console.WriteLine("midjji method result:   \t" + c3 + ", time elapsed in ms: \t" + time3.TotalMilliseconds);
		Console.WriteLine("Single HashSet method result: \t" + c4 + ", time elapsed in ms: \t" + time4.TotalMilliseconds);
		Console.WriteLine("Many HashSets method result: \t" + c5 + ", time elapsed in ms: \t" + time5.TotalMilliseconds);
	}

	static int SharedEdgeCount1(int[] tris0, int[] tris1) {
		var count = 0;
		for (int t = 0; t < tris0.Length; t+=3) {
			var x0 = tris0[t];
			var x1 = tris0[t+1];
			var x2 = tris0[t+2];

			var y0 = tris1[t];
			var y1 = tris1[t+1];
			var y2 = tris1[t+2];

			if (x0 == y0) {
				if (x1 == y1 || x1 == y2 || x2 == y1 || x2 == y2) count++;
			} else if (x0 == y1) {
				if (x1 == y0 || x1 == y2 || x2 == y0 || x2 == y2) count++;
			} else if (x0 == y2) {
				if (x1 == y0 || x1 == y1 || x2 == y0 || x2 == y1) count++;
			} else {
				if ((x1 == y0 && x2 == y1) 
						|| (x1 == y0 && x2 == y2)
						|| (x1 == y1 && x2 == y0)
						|| (x1 == y1 && x2 == y2)
						|| (x1 == y2 && x2 == y0)
						|| (x1 == y2 && x2 == y1)) {
				   
					count++;
				}
			}
		}

		return count;
	}

	static int SharedEdgeCount2(int[] tris0, int[] tris1) {
		var count = 0;
		for (int t = 0; t < tris0.Length; t+=3) {
			var x0 = tris0[t];
			var x1 = tris0[t+1];
			var x2 = tris0[t+2];

			var y0 = tris1[t];
			var y1 = tris1[t+1];
			var y2 = tris1[t+2];

			int n = 0;

			// check if x0 is among the values in the second set
			if (x0 == y0 || x0 == y1 || x0 == y2) {
				n++;
			}

			// check if x1 is among the values in the second set
			if (x1 == y0 || x1 == y1 || x1 == y2) {
				n++;
			}

			// check if x2 is among the values in the second set
			if (x2 == y0 || x2 == y1 || x2 == y2) {
				n++;
			}

			if (n >= 2) count++;
		}

		return count;
	}

	static int SharedEdgeCount3(int[] tris0, int[] tris1) {
		var count = 0;

		for (int t = 0; t < tris0.Length; t+=3) {
			var x0 = tris0[t];
			var x1 = tris0[t+1];
			var x2 = tris0[t+2];

			var y0 = tris1[t];
			var y1 = tris1[t+1];
			var y2 = tris1[t+2];

			bool t0= (x0==y0) ||(x0==y1)|| (x0==y2);
			bool t1= (x1==y0) ||(x1==y1)|| (x1==y2);
			bool t2= (x2==y0) ||(x2==y1)|| (x2==y2);

			if ((t0 && t1) || (t0 && t2) || (t1 && t2)) {
				count++;
			}
		}

		return count;
	}

	static int SharedEdgeCount4(int[] tris0, int[] tris1) {
		var count = 0;
		
		var set = new HashSet<int>();

		for (int t = 0; t < tris0.Length; t+=3) {
			var x0 = tris0[t];
			var x1 = tris0[t+1];
			var x2 = tris0[t+2];

			var y0 = tris1[t];
			var y1 = tris1[t+1];
			var y2 = tris1[t+2];

			set.Clear();

			set.Add(y0);
			set.Add(y1);
			set.Add(y2);

			var n = 0;

			if (set.Contains(x0)) n++;
			if (set.Contains(x1)) n++;
			if (set.Contains(x2)) n++;

			if (n >= 2) count++;
		}

		return count;
	}

	static int SharedEdgeCount5(int[] tris0, int[] tris1) {
		var count = 0;
		

		for (int t = 0; t < tris0.Length; t+=3) {
			var set = new HashSet<int>();
			var x0 = tris0[t];
			var x1 = tris0[t+1];
			var x2 = tris0[t+2];

			var y0 = tris1[t];
			var y1 = tris1[t+1];
			var y2 = tris1[t+2];

			set.Add(y0);
			set.Add(y1);
			set.Add(y2);

			var n = 0;

			if (set.Contains(x0)) n++;
			if (set.Contains(x1)) n++;
			if (set.Contains(x2)) n++;

			if (n >= 2) count++;
		}

		return count;
	}
}