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Return None if Dictionary key is not available
I need a way to get a dictionary value if its key exists, or simply return None , if it does not.
11 Answers
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design a stack such that getMinimum( ) should be O(1)
.... Note that this doesn't change the complexity of the space required, e.g. if you've got a stack with O(n) space requirements, this will still be O(n) just with a different constant factor.
Non-constant-space solution
Keep a "duplicate" stack of "minimum of all values lower in the stack". When you...
How do C++ class members get initialized if I don't do it explicitly?
...emebers ptr , name , pname , rname , crname and age . What happens if I don't initialize them myself? Here is an example:
...
Does VBA have Dictionary Structure?
...ictionary")
or
Dim dict As New Scripting.Dictionary
Example of use:
If Not dict.Exists(key) Then
dict.Add key, value
End If
Don't forget to set the dictionary to Nothing when you have finished using it.
Set dict = Nothing
...
Why is Python running my module when I import it, and how do I stop it?
...t declarations. Instead, they are real live statements which are executed. If they were not executed your module would be .. empty :-)
Anyway, the idiomatic approach is:
# stuff to run always here such as class/def
def main():
pass
if __name__ == "__main__":
# stuff only to run when not ca...
In C# check that filename is *possibly* valid (not that it exists) [duplicate]
...tch (System.IO.PathTooLongException) { }
catch (NotSupportedException) { }
if (ReferenceEquals(fi, null)) {
// file name is not valid
} else {
// file name is valid... May check for existence by calling fi.Exists.
}
For creating a FileInfo instance the file does not need to exist.
...
How do I get the first element from an IEnumerable in .net?
...
If you can use LINQ you can use:
var e = enumerable.First();
This will throw an exception though if enumerable is empty: in which case you can use:
var e = enumerable.FirstOrDefault();
FirstOrDefault() will return defau...
Event handling for iOS - how hitTest:withEvent: and pointInside:withEvent: are related?
... UIResponder does the following:
It calls pointInside:withEvent: of self
If the return is NO, hitTest:withEvent: returns nil. the end of the story.
If the return is YES, it sends hitTest:withEvent: messages to its subviews.
it starts from the top-level subview, and continues to other views until a...
AJAX in Chrome sending OPTIONS instead of GET/POST/PUT/DELETE?
...
Chrome is preflighting the request to look for CORS headers. If the request is acceptable, it will then send the real request. If you're doing this cross-domain, you will simply have to deal with it or else find a way to make the request non-cross-domain. This is why the jQuery bug was...
break out of if and foreach
I have a foreach loop and an if statement. If a match is found i need to ultimately break out of the foreach.
4 Answers
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