Given two inclusive ranges [x1:x2] and [y1:y2], where x1 ≤ x2 and y1 ≤ y2, what is the most efficient way to test whether there is any overlap of the two ranges? A simple implementation is as follows: bool testOverlap(int x1, int x2, int y1, int y2) { return (x1 >= y1 && x1 <= … Read more
Suppose I have a std::vector (let’s call it myVec) of size N. What’s the simplest way to construct a new vector consisting of a copy of elements X through Y, where 0 <= X <= Y <= N-1? For example, myVec [100000] through myVec [100999] in a vector of size 150000. If this cannot be … Read more
I am getting an error when running a python program: Traceback (most recent call last): File “C:\Program Files (x86)\Wing IDE 101 4.1\src\debug\tserver\_sandbox.py”, line 110, in <module> File “C:\Program Files (x86)\Wing IDE 101 4.1\src\debug\tserver\_sandbox.py”, line 27, in __init__ File “C:\Program Files (x86)\Wing IDE 101 4.1\src\debug\tserver\class\inventory.py”, line 17, in __init__ builtins.NameError: global name ‘xrange’ is not defined … Read more
>>> range(1,11) gives you [1,2,3,4,5,6,7,8,9,10] Why not 1-11? Did they just decide to do it like that at random or does it have some value I am not seeing? 10 Answers 10
I’ve been updating some of my old code and answers with Swift 3 but when I got to Swift Strings and Indexing with substrings things got confusing. Specifically I was trying the following: let str = “Hello, playground” let prefixRange = str.startIndex..<str.startIndex.advancedBy(5) let prefix = str.substringWithRange(prefixRange) where the second line was giving me the following … Read more
Why or why not? Best Answers 12 For performance, especially when you’re iterating over a large range, xrange() is usually better. However, there are still a few cases why you might prefer range(): In python 3, range() does what xrange() used to do and xrange() does not exist. If you want to write code that … Read more
How can you produce the following list with range() in Python? [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] 19 Answers 19 use reversed() function: reversed(range(10)) It’s much more meaningful. Update: If you want it to be a list (as btk pointed out): list(reversed(range(10))) Update: If you want to use only range to … Read more
Apparently xrange is faster but I have no idea why it’s faster (and no proof besides the anecdotal so far that it is faster) or what besides that is different about for i in range(0, 20): for i in xrange(0, 20): 28 s 28 In Python 2.x: range creates a list, so if you do … Read more
Is there a way to step between 0 and 1 by 0.1? I thought I could do it like the following, but it failed: for i in range(0, 1, 0.1): print(i) Instead, it says that the step argument cannot be zero, which I did not expect. 34 s 34
How can I check if a string (NSString) contains another smaller string? I was hoping for something like: NSString *string = @”hello bla bla”; NSLog(@”%d”,[string containsSubstring:@”hello”]); But the closest I could find was: if ([string rangeOfString:@”hello”] == 0) { NSLog(@”sub string doesnt exist”); } else { NSLog(@”exists”); } Anyway, is that the best way to … Read more
