var list1 = new List<int> { , , , , , , ,  };

var list2 = new List<int> { , , , , , , , ,  };

// List1:1 3 5 7 9 11 13 15

Console.WriteLine("List1:" + string.Join("\t", list1));

// List2:1 2 3 4 5 6 7 8 9

Console.WriteLine("List2:" + string.Join("\t", list2));

// 差集-List1有List2无:11 13 15

Console.WriteLine("差集-List1有List2无:" + string.Join("\t", list1.Except(list2)));

// 交集-List1有List2有:1 3 5 7 9

Console.WriteLine("交集-List1有List2有:" + string.Join("\t", list1.Intersect(list2)));

// 并集-包含List1和List2:1 3 5 7 9 11 13 15 2 4 6 8

Console.WriteLine("并集-包含List1和List2:" + string.Join("\t", list1.Union(list2)));

Console.ReadLine();