We see through the books that there are numerous ways to get in and out of Hogwarts:   By Train Flying car Secret passage to Hogsmeade Through the lake Through vanishing cabinet   It looks like there are a lot of way to get in and out of Hogwarts (except apparition).  What was the reason for such a complex plan (tweaking goblet, helping Harry to win, taking control over Harry's opponents)? It feels like it would be much simpler for fake Moody to just knock Harry on his head and walk away with him.
In Harry Potter and the Goblet of Fire the Triwizard Cup was used as the portkey to send Harry and Cedric to the graveyard in Little Hangleton to face Voldemort.    Why was the Triwizard Cup chosen?    Couldn't Crouch Jr. have used anything as a portkey; which would have been much easier and without as much risk (after all of their planning Cedric almost ended up getting the cup first).
Accessing laptop's hard drive when OS won't boot Python and regular expression with Unicode I need to delete some Unicode symbols from the string 'بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ'  I know they exist here for sure. I tried:  re.sub('([\u064B-\u0652\u06D4\u0670\u0674\u06D5-\u06ED]+)', '', 'بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ')   but it doesn't work. String stays the same. What am I doing wrong? In C++/CLI, what does the hat character ^ do? I was reading Ivor Horton's Beginning Visual C++ 2008 and many of its CLR examples have this definition for main:  int main(array&lt;System::String ^&gt; ^args)   I went back, page by page, to the beginning of the book to find the first such instance with an explanation what it really means, but couldn't find one.  Obviously it means the same as the standard int main(int argc, char *argv[]), but I'd like to know when and why that ^ is really used, and why it even exists (does it do something that pointers * and references &amp; cannot represent)? How to parse JSON in Java WITH ROLLUP WHERE x IS NULL Compact vs Mirrorless - why pick one over another? What would be a reason for one to pick the compact (whatever it'd be P&amp;S or something more advanced) over mirrorless compact system camera  ?  Right now market is quite confusing — we have huge market of tiny-sensor compacts, we have mirrorless that use sensors in a size of these from P&amp;S cameras (Nikon 1 being notable example), we have compacts with sensors bigger than most popular mirrorless system (Canon G1X vs m4/3), we have lot of APS-C sensor mirrorless which are matched by some of the compacts (Fuji X100 being most notable example, but even Leica has its X2),  and to make it even more confusing — Sony released RX1 with full frame sensor, beating crap out of every mirrorless on a market.  So what are your arguments to pick compact over a mirrorless?  Why are they better, what's the reason behind logic of companies like Fujifilm which at the same time offers P&amp;S and X-mount mirrorless using same sensor size? Work the Spring There's a book that I read several years ago that I'd like to find.  However, I cannot remember enough about it to find it myself.  Neither the title nor author remain in my mind, nor any keyword or phrase that's unique enough for the Grand Google to nail for me.  Hence my desperate plea here.  In the book, there is an interstellar civilization composed of several power blocks.  The entire civilization did not fill the galaxy, but it did span several stellar systems.  Maybe 10s or 100s.  I seem to remember that one of the civilizations was a decentralized group referred to as the Brotherhood and they seemed to have been keen on preserving old learning and political ideals.  A derelict alien spacecraft from outside all of this had been discovered and at least two of the power blocks sent ships to recover it.  I don't recall if they knew at the time about the power the alien ship had, but they must have had some clue since there was some urgency in capturing this ship.  One of the ships sent to capture the Alien craft was commanded by somebody who was rather shaken up, to say the least.  He had had some big trauma in his past (like... the last ship he captained was annihilated with all hands.) so he was kinda bummed out about things and wasn't really putting his heart into getting this done.  He was assisted by the ship's AI who had a lot of soul-to-soul chats with the captain, and at one point almost relieved him of command because he was just not getting the job done.  I think the ship's name was Boaz.  These were the "good guys".  There was at least one other ship sent from the "bad guys."  The alien craft had some remarkable powers.  The interior volume was apparently infinite and the operators could see and manipulate anything in the universe.  There might have been some example given where all the rats somewhere were found and disposed of.  Whoever had control was tempted by the ole absolute power corrupts absolutely problem, but nobody but nobody could stop them because of their power.  They could eat and multiply within the ship and become real bad-asses.  But alas... (or hurray, depending upon which side you're one) everything fails eventually, and whoever controlled the ship would eventually succumb to some horrible end.  Whereupon the ship became derelict again until some other lucky race found it and repeated the cycle.  The ship had an AI that was real interested in taking the power for itself, but there was some mechanical, spring-loaded, mechanism outside of its control that needed to be worked in order to execute power.  The AI apparently never figured out how to "work the spring" and this made him crazy angry.  The ending is equally foggy for me.  I'm pretty sure the good guys got the ship.  They agonized over what to do with it.  Apparently it was indestructable and nobody wanted to taste the temptation of all that power.  In the end they dumped it on the surface of a neutron star.  There it sat forever more, probably with the crazy AI really pissed off about being there.  If you've read this book, you'll recognize it immediately from these clues.  I'm looking forward to finding out the name of this book.  Thanks! Why was my flag declined? I've recently flagged the following , which I got in the flag queue.   The answer does not seem to attempt to address the question at all. It looks like a comment on one of the other answers (probably Luca's).  It got rejected with the following reason:  declined - flags should not be used to indicate technical inaccuracies,            or an altogether wrong answer   I did not flag this because I thought it was wrong, I flagged it because I didn't think it was an attempt to answer the question. For what it's worth, I don't get what the guy who provided that answer even tried to say.  Was I wrong to flag it? If so why? Counting unique records across 2 columns and computing a score based on boolean values I have a table that looks like this in Google Big Query:  custID  InteractionDate Purchased?  Sales 1       20150312           F         0 1       20150312           T         200 1       20150314           T         150 2       20150221           T         400 2       20150221           F         0 2       20150221           T         120   ..that I need to transform to the following structure:   custID InteractionDate Success Sales  1     20150312          0.5    200  1     20150314           1     150  2     20150221         0.66    520   ..where in this second table the success column is defined as  count(purchase=Yes)/(count(purchase=Yes) + count(purchase=No)),   and sales is just the sum.  I'm quite new to BQ and no-SQL languages. I simply don't know how to do this, I've searched and seen examples that suggest using partition over but I simply haven't seen any example that does just this. Thanks a lot in advance. Suggested edit review should show custom rejection reasons Somewhat similar to , but rather more limited: when Rejecting an edit, not only the count of custom rejection reasons but the actual text of the reasons should be shown, IMO. Just now I  on SO that tidied some code in a trivially correct and substantially superior way because it looked perfectly legitimate and I couldn't understand why anyone would bother with a custom rejection reason. As it turned out, it was code in a question, of course.  In this case, the rejection reason correctly identified the problem, and had I seen it, I would have been reminded of that aspect I had neglected to check. Is there a max array length limit in C++? Statistics module doesn't show the "Enable access log" checkbox I dont know what to do to show "Enable access log" option.  I activated logging all messages and checked all statistics permissions.  Thanks. Eclipse is giving me a warning of the following form:     Type safety: Unchecked cast from Object to HashMap   This is from a call to an API that I have no control over which returns Object:  HashMap&lt;String, String&gt; getItems(javax.servlet.http.HttpSession session) {   HashMap&lt;String, String&gt; theHash = (HashMap&lt;String, String&gt;)session.getAttribute("attributeKey");   return theHash; }   I'd like to avoid Eclipse warnings, if possible, since theoretically they indicate at least a potential code problem.  I haven't found a good way to eliminate this one yet, though.  I can extract the single line involved out to a method by itself and add @SuppressWarnings("unchecked") to that method, thus limiting the impact of having a block of code where I ignore warnings.  Any better options?  I don't want to turn these warnings off in Eclipse.  Before I came to the code, it was simpler, but still provoked warnings:  HashMap getItems(javax.servlet.http.HttpSession session) {   HashMap theHash = (HashMap)session.getAttribute("attributeKey");   return theHash; }   Problem was elsewhere when you tried to use the hash you'd get warnings:  HashMap items = getItems(session); items.put("this", "that");  Type safety: The method put(Object, Object) belongs to the raw type HashMap.  References to generic type HashMap&lt;K,V&gt; should be parameterized. Launching an Applet fails? Convergence of $\int_0^\infty $sin$ (x^p) dx$ In the early days of C++ when it was bolted on top of C, you could not use NULL as it was defined as (void*)0. You could not assign NULL to any pointer other than void*, which made it kind of useless. Back in those days, it was accepted that you used 0 (zero) for null pointers.  To this day, I have continued to use zero as a null pointer but those around me insist on using NULL. I personally do not see any benefit to giving a name (NULL) to an existing value - and since I also like to test pointers as truth values:  if (p &amp;&amp; !q)   do_something();   then using zero makes more sense (as in if you use NULL, you cannot logically use p &amp;&amp; !q - you need to explicitly compare against NULL, unless you assume NULL is zero, in which case why use NULL).  Is there any objective reason to prefer zero over NULL (or vice versa), or is all just personal preference?  Edit: I should add (and meant to originally say) that with RAII and exceptions, I rarely use zero/NULL pointers, but sometimes you do need them still. Invocable method Apex class is not visible in Process builder At 12 o'clock, the hour hand and minute hand of the clock can be swapped, and the clock still gives the same time, but at 6 o'clock, it can not be swapped. So in what cases when we swap the hour and the minute hand position does a clock still give a valid time? iPhone screen randomly turns on Zsh get terminfo keys with modifiers