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Why doesn't Dijkstra's algorithm work for negative weight edges?
Can somebody tell me why Dijkstra's algorithm for single source shortest path assumes that the edges must be non-negative.
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Why use argparse rather than optparse?
I noticed that the Python 2.7 documentation includes yet another command-line parsing module. In addition to getopt and optparse we now have argparse .
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How to use Greek symbols in ggplot2?
My categories need to be named with Greek letters. I am using ggplot2 , and it works beautifully with the data. Unfortunately I cannot figure out how to put those greek symbols on the x axis (at the tick marks) and also make them appear in the legend. Is there any way to do it?
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Binding a WPF ComboBox to a custom list
I have a ComboBox that doesn't seem to update the SelectedItem/SelectedValue.
4 Answers
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Named regular expression group “(?Pregexp)”: what does “P” stand for?
In Python, the (?P<group_name>…) syntax allows one to refer to the matched string through its name:
3 Answers
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Detect encoding and make everything UTF-8
I'm reading out lots of texts from various RSS feeds and inserting them into my database.
24 Answers
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How to write a Python module/package?
I've been making Python scripts for simple tasks at work and never really bothered packaging them for others to use. Now I have been assigned to make a Python wrapper for a REST API. I have absolutely no idea on how to start and I need help.
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Which comment style should I use in batch files?
I've been writing some batch files, and I ran into this user guide , which has been quite informative. One thing it showed me was that lines can be commented not just with REM , but also with :: . It says:
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Unignore subdirectories of ignored directories in Git
Let's say I have ignored a directory, but I want to unignore specific subdirectories therein. So I have the setup:
5 Answer...
typedef fixed length array
I have to define a 24-bit data type.I am using char[3] to represent the type. Can I typedef char[3] to type24 ? I tried it in a code sample. I put typedef char[3] type24; in my header file. The compiler did not complain about it. But when I defined a function void foo(type24 val) {} in my C...