C # list<t> intersection, continuous set and difference set

※ This article uses int as an example, if you use a custom Datamodel, you need to actually use the Iequatable<t> interface.

1. Take intersection (A and b are both)

List A: {1, 2, 3, 5, 9}

List B: {4, 3, 9}

1	var intersectedList = list1.Intersect(list2);

Outcome: {3, 9}

To see if A and b intersect.

1	boolisIntersected = list1.Intersect(list2).Count() > 0

2. Take the difference set (a Yes, B No)

List A: {1, 2, 3, 5, 9}

List B: {4, 3, 9}

1	var expectedList = list1.Except(list2);

Results: {1, 2, 5}

Whether A and B have a difference set

1	boolisExpected = list1.Expect(list2).Count() > 0

3. Collecting the Union (contains a and b)

List A: {1, 2, 3, 5, 9}

List B: {4, 3, 9}

01	publicstatic classListExtensions

02

{

03	publicstatic List<T> Merge<T>(thisList<T> source, List<T> target)

04

{

05	List<T> mergedList = newList<T>(source);

06

07	mergedList.AddRange(target.Except(source));

08

09	returnmergedList;

10

}

11

}

1	var mergedList = list1.Merge(list2);

Results: {1, 2, 3, 5, 9, 4}

※6/15 supplement: Thank Rou torn greatly reminded that LINQ has built-in method union is desirable!

Language

Using LINQ, you can easily do a list's comparison,

If you have any questions, welcome to the discussion:)

Reproduced in: http://www.cnblogs.com/liguanghui/archive/2011/11/09/2242309.html

During the development process. The handling of arrays and collections is the most worrying. Some operations are typically handled with a for or foreach. Here are some commonly used sets and arrays of operation functions.

First, for example, 2 sets, A, B.

list<int> ListA = new list<int> {1,2,3,5,7,9};

list<int> Listb = new list<int> {13,4,17,29,2};

Lista.addrange (LISTB); Merges the collection a.b list<int> Result = lista.union (LISTB).          Tolist<int> (); Reject duplicates list<int> Result = Lista.concat (LISTB).        Tolist<int> (); Keep Duplicates

Lista.binarysearch ("1");//Determines whether a value is included in the collection. Returns 0 if included

In an example of two arrays

Int[] I=new int[]{1,2};  Int[] J=new int[]{2,3}; list<int> r = new list<int> ();

R.addrange (i);

R.addrange (j);

Int[] C = R.toarray (); Merging arrays

Int[] X=i.union (j). Toarray<int> (); Reject Duplicates

Int[] X=i.concat (j). Toarray<int> (); Keep Duplicates

int n = array.binarysearch (i,3);//Determines whether a value is included in the array. Returns 0 if included

C # intersection, list<t>, and difference sets for a set