Bill Gates launches stealth bgC3 LLC project

Wish he would add Hash and Merge Joins...

.. to in memory Linq first.

private string test(int c)

{

List<int> list1 = new List<int>() { 3, 1, 2, 6, 7, 8, 30 };

List<int> list2 = new List<int>() { 4, 5, 2, 2, 7, 9, 30 };

(from l1 in list1 from l2 in list2 select (l1 * l2 + 111) % 77).ToList<int>().ForEach(n => { if (list1.Count < c) list1.Add(n); });

(from l1 in list1 from l2 in list2 select (l1 * l2 + 111) % 77).ToList<int>().ForEach(n => { if (list2.Count < c) list2.Add(n); });

(from l1 in list1 from l2 in list2 select (l1 * l2 + 111) % 77).ToList<int>().ForEach(n => { if (list1.Count < c) list1.Add(n); });

(from l1 in list1 from l2 in list2 select (l1 * l2 + 111) % 77).ToList<int>().ForEach(n => { if (list2.Count < c) list2.Add(n); });

Stopwatch s = new Stopwatch();

s.Start();

int lLoop = InnerLoopJoin(list1, list2);

s.Stop();

long tLoop = s.ElapsedMilliseconds;

s.Reset();

s.Start();

int lHash = InnerHashJoin(list1, list2);

s.Stop();

long tHash = s.ElapsedMilliseconds;

s.Reset();

return "Hash = " + tHash.ToString() + " Loop = " + tLoop.ToString();

}

private void button1_Click(object sender, EventArgs e)

{

StringBuilder sb = new StringBuilder();

for (int i = 100; i < 4000; i += 100)

listBox1.Items.Add(i.ToString() + test(i));

}

private int InnerLoopJoin(List<int> list1, List<int> list2)

{

var x =

from l1 in list1

from l2 in list2

where l1 == l2

select new { l1, l2 };

return x.Count();

}

private int InnerHashJoin(List<int> list1, List<int> list2)

{

Dictionary<int, int> d = (from l1 in list1 group l1 by l1 into g select g).ToDictionary(n => n.Key, n => n.Count());

var x =

from l2 in list2

where d.ContainsKey (l2)

from i in Enumerable.Range (1, d[l2])

select new { l1 = l2, l2 };

return x.Count();

}

private int MergeJoin(List<int> list1, List<int> list2)

{

// var x =

// from

return 0;

}