intersection

Can someone explain how to check if one rotated rectangle intersect other rectangle ? For each edge in both polygons, check if it can be used as a separating line. If so, you are done: No intersection. If no separation line was found, you have an intersection. /// Checks if the two polygons are intersecting. bool IsPolygonsIntersecting(Polygon a, Polygon b) { foreach (var polygon in new[] { a, b }) { for (int i1 = 0; i1 < polygon.Points.Count; i1++) { int i2 = (i1 + 1) % polygon.Points.Count; var p1 = polygon.Points[i1]; var p2 = polygon.Points[i2]; var normal = new Point(p2.Y - p1.Y, p1.X -

Intersect can be used to find matches between two collections, like so: // Assign two arrays. int[] array1 = { 1, 2, 3 }; int[] array2 = { 2, 3, 4 }; // Call Intersect extension method. var intersect = array1.Intersect(array2); // Write intersection to screen. foreach (int value in intersect) { Console.WriteLine(value); // Output: 2, 3 } However what I'd like to achieve is the opposite, I'd like to list the items that are missing when comparing two collections: // Assign two arrays. int[] array1 = { 1, 2, 3 }; int[] array2 = { 2, 3, 4 }; // Call Intersect extension method. var intersect =

I want to check if any of the items in one list are present in another list. I can do it simply with the code below, but I suspect there might be a library function to do this. If not, is there a more pythonic method of achieving the same result. In [78]: a = [1, 2, 3, 4, 5] In [79]: b = [8, 7, 6] In [80]: c = [8, 7, 6, 5] In [81]: def lists_overlap(a, b): ....: for i in a: ....: if i in b: ....: return True ....: return False ....: In [82]: lists_overlap(a, b) Out[82]: False In [83]: lists_overlap(a, c) Out[83]: True In [84]: def lists_overlap2(a, b): ....: return len(set(a).intersection(set

Possible Duplicate: Efficiently finding the intersection of a variable number of sets of strings Say, have two Hashset, how to calculate the intersection of them? Set<String> s1 = new HashSet<String>(); Set<String> s2 = new HashSet<String>(); S1 INT S2 ? Use the retainAll() method of Set : Set<String> s1; Set<String> s2; s1.retainAll(s2); // s1 now contains only elements in both sets If you want to preserve the sets, create a new set to hold the intersection: Set<String> intersection = new HashSet<String>(s1); // use the copy constructor intersection.retainAll(s2); The javadoc of retainAll()