Passing contents of file on the command line for c++ program
How to delete files listed in a text file
No cycle containing edges $e$ and $g$ implies there is a vertex $u$ so that every path sharing one end with $e$ and another with $g$ contains $u$ There is a proof in my textbook for the following claim, which doesn't make a whole lot of sense to me.  My annotations are in bold.  Could someone perhaps elaborate on what's going on?  Claim.  If there does not exist a cycle containing edges $e$ and $g$ then there exists a vertex $u \in V (G)$ such that every path in $G$ sharing one end with e and another with $g$ contains $u$.  Proof: The claim trivially holds if $e$ or $g$ is a loop OK, so we assume that neither is. Let $P$ with vertex set $v_1, v_2, . . . , v_k,$ in order, be a path with $e$ joining $v_1$ to $v_2$ and $g$ joining $v_{k−1}$ and $v_k$. Let $f_i \in E(P_i)$ be the edge with ends $v_i$ and $v_{i+1}$. Let $j$ be chosen minimum so that no cycle in $G$ contains $e$ and $f_j$ We can do this because we know that at least the edge $g$ will not create a cycle by assumption, right?. We will show that $u = v_j$ satisfies the claim.  Suppose not. Let $C$ be a cycle containing $e$ and $f_{j−1}$ What if $f_j = e$?  then what cycle? a single vertex? and let $P′$ be a path from an end of $e$ to an end of $f$ Not sure what the book meant by $f$ here, any guesses? avoiding $u$. Choose a subpath $Q$ of $P′$ with one end in $V (C)$ and another in ${v_{j+1}, v_{j+2}, . . . , v_k}$ as short as possible. Then $C \cup Q \cup P$ contains a cycle containing both $e$ and $f_j$, a contradiction. (The last statement requires some case checking.) This ending seems a bit abrupt and non-obvious to me  Thanks for the help There's another question on physics.SE whose , if I have understood it correctly, explains that the farther the points are in space the faster they are moving away from each other.     Actually, the apparent speed with which two of the points on the   circle in a distance $D$ of each other would move relative to each   other will be $v = H_0 D$ where $H_0$ is the speed the balloon itself   is expanding.   This means that even the ruler sitting on my desk is expanding, just that the expansion is very very slow owing to the ruler's small size relative to the cosmic scales. However, if everything is scaling then everything should apparently be of the same size to an observer in such an expanding space. The  quote from the show "The Big Bang Theory" comes to mind.   To be able to counter that, there're some phenomena that we can observe which are scale invariant. Red-shift would be one such phenomenon. But is red-shift the only way we can tell that the space is expanding? Is there a logical flaw in my thinking? I know that red-shift is a result of the Doppler effect - there's bound to be a decrease in the frequency of a signal, as perceived by an observer, emitted by a source which is moving away relative to the observer. Wrong favicon displayed on Google's mobile SERP For some time now, Google has been displaying a website's favicon next to its title on the mobile SERP according to    But, for one website that I am managing, it is showing a completely different favicon. You can see it if you open the  on a mobile device, I am talking about the orange one:  I am referring to the top result.  As you can see on the , the favicon has been added correctly using the proper meta tag:   &lt;link  rel="icon" type="image/x-icon" href="https://www.hoofgroove.ch/pub/media/favicon/default/favicon.ico" /&gt;   This is according to .  Also, all the browsers are displaying the correct favicon, which is not the orange one but the black&amp;red one.  This meta tag has been used for weeks and also the  has always been the correct one as far as I can tell.  But for some reason, Google is showing the wrong favicon on its mobile SERP.  Any ideas why? How do you force constructor signatures and static methods? Is there a way of forcing a (child) class to have constructors with particular signatures or particular static methods in C# or Java?  You can't obviously use interfaces for this, and I know that it will have a limited usage. One instance in which I do find it useful is when you want to enforce some design guideline, for example:  Exceptions They should all have the four canonical constructors, but there is no way to enforce it. You have to rely on a tool like FxCop (C# case) to catch these.  Operators There is no contract that specifies that two classes can be summed (with operator+ in C#)  Is there any design pattern to work around this limitation? What construct could be added to the language to overcome this limitation in future versions of C# or Java? The separation between the two plates of a capacitor is increased I had the following question on a quiz recently:     A capacitor consisting of two parallel plates, separated by a distance $d$, is connected to a battery of EMF ε. What happens if the separation is doubled while the battery remains connected?    The correct answer was "The electric charge on the plates is halved." However, we were previously given a question in which a circuit consists of a capacitor of 6 μF and a resistor of 300,000 Ω connected to a battery, and the separation between the plates of the capacitor is quadrupled. However, in this circumstance, the charge on the capacitor immediately after the plates are separated remains the same, and the potential difference across the capacitor increases.   I am confused as to why these questions have different answers to them, despite having an extremely similar setup. My best guess is that the circuit in the second question also has a resistor, but I am not sure, and help would be greatly appreciated. Can a well-timed Twisted Image kill a player using Tree of Redemption? What happens if my opponent activates  and I cast  with the life-exchange ability on the stack?  Looking at the comp rules, these seem most relevant:     701.8a A spell or ability may instruct players to exchange something (for example, life totals or    control of two permanents) as part of   its resolution. When such a spell or ability resolves, if the   entire exchange can’t be completed, no part of the exchange occurs.      Example: If a spell attempts to exchange control of two target creatures but one of those              creatures is destroyed before the spell resolves, the spell does nothing to the other              creature.      112.7a Once activated or triggered, an ability exists on the stack independently of its source.    Destruction or removal of the source   after that time won’t affect the ability. Note that some    abilities   cause a source to do something (for example, “Prodigal Sorcerer deals   1 damage to    target creature or player”) rather than the ability   doing anything directly. In these cases, any    activated or triggered   ability that references information about the source because the   effect    needs to be divided checks that information when the ability   is put onto the stack. Otherwise, it    will check that information   when it resolves. In both instances, if the source is no longer in the   zone it’s expected to be in at that time, its last known information   is used. The source can still    perform the action even though it no   longer exists.   Is the entire exchange ability countered because the Tree is dead by the time it resolves? Or do we use the "last known state" (toughness 0), thereby killing its controller? What requests do browsers' "F5" and "Ctrl + F5" refreshes generate? Is there a standard for what actions F5 and Ctrl + F5 trigger in web browsers?  I once did experiment in IE6 and Firefox 2.x. The F5  refresh would trigger a HTTP request sent to the server with an If-Modified-Since header, while Ctrl + F5 would not have such a header. In my understanding, F5  will try to utilize cached content as much as possible, while Ctrl + F5  is intended to abandon all cached content and just retrieve all content from the servers again.   But today, I noticed that in some of the latest browsers (Chrome, IE8) it doesn't work in this way anymore. Both F5 and Ctrl + F5 send the If-Modified-Since header.   So how is this supposed to work, or (if there is no standard) how do the major browsers differ in how they implement these refresh features? I've found a nasty VBS way to do this, but I'm looking for a native PoSh procedure to edit the properties of a .LNK file.  The goal is to reach out to remote machines, duplicate an existing shortcut with most of the correct properties, and edit a couple of them.  If it would just be easier to write a new shortcut file, that would work too. I have studied from Griffiths, the relativistic form of momentum is $$p = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}} m_0v$$   Now when I evaluate the momentum for photon, I just insert $v=c$ and $m_0=0$ and I get $p= 0/0$. How does it make sense?   Can you tell me that where I am wrong? How to share an encrypted storage on Windows, Mac OS X and Linux in a secure way I got a 2 TB drive that I have to use with both Windows 8.1 / Windows 10 and Yosemite to OS X / OS X El Capitan and maybe even on Linux.  I need to encrypt the volume. Or rather, I want to create two partitions: a 1.7 TB encrypted and unencrypted the remaining space.  Now I use Windows BitLocker to 512bit. On Mac and Linux nothing, obviously.  What do you recommend?  I saw TrueCrypt (and I read about all the confusion created after May 2014), of VeraCrypt, of GNUPG, Disklocker to read BitLocker on Unix.  But I feel lost and without a good idea.  And if I use TrueCrypt 7.1a waiting for new solutions such as precautions to prevent memory dumps and other potential crack?  And then how should I use TrueCrypt to format the drive? In GPT? MBR? Journaled? FAT? Apache doesn't log remoteIP when RemoteIPHeader X-Forwarded-For is present Why do I get blurry pictures when I take a lens attachment off? What is the possibility of a railgun assisted orbital launch? Basic facts: The  is 2.4 miles deep.  Railguns  of a projectile on the order of 7.5 km/s.  The Earth's  is 11.2 km/s.  It seems to me that a railgun style launch device built into a deep shaft such as an abandoned mine could reasonably launch a vehicle into space.  I have not run the calculations and I wouldn't doubt that there might be issues with high G's that limit the potential for astronauts on such a vehicle, but even still it seems like it would be cheaper to build such a launch device and place a powerplant nearby to run it than it is to build and fuel single-use rockets.  So, what is the possibility of a railgun assisted orbital launch?   What am I missing here?  Why hasn't this concept received more attention? Delete specific line number(s) from a text file using sed? How to fill down in Numbers without dragging? I have association bonus on superuser.com. After that I've started a bounty worst of 50 rep and earned more than 10 rep. Now I have 89 rep (38 of which is earned at superuser which is more than 10) but still not able to answer protected questions.  So, currently new user with 10 rep can answer protected question and I with 89 (38) rep can't.   How does it work now: after registration on new Stack Exchange site you get 101 rep Association Bonus and are able to answer protected questions only when you have 111+ rep on that site. How should it work: after registration on new stackexchange site you get 101 rep Association Bonus and are able to answer protected questions only when you have earned 10+ rep on that site. Can photons be detected without being absorbed? I am thinking about a detector that would beep if light passes through it. Is it possible? As mentioned in many of my previous questions, I'm working through K&amp;R, and am currently into the preprocessor. One of the more interesting things &mdash; something I never knew before from any of my prior attempts to learn C &mdash; is the ## preprocessor operator. According to K&amp;R:     The preprocessor operator ##   provides a way to concatenate actual   arguments during macro expansion. If a   parameter in the replacement text is   adjacent to a ##, the parameter is   replaced by the actual argument, the   ## and surrounding white space are   removed, and the result is re-scanned.   For example, the macro paste   concatenates its two arguments:      #define  paste(front, back)  front ## back      so paste(name, 1) creates the token   name1.   How and why would someone use this in the real world? What are practical examples of its use, and are there gotchas to consider? How can I capture the movement of a bullet? Just beginning with photography.    Consider this image:     (This photo was taken by Harold "Doc" Edgerton in 1964 using his Rapatronic camera.)  I am looking for a  camera that can capture such an image. I am not looking for more fps. less fps is fine, but it must be able to capture such an instance.   What features should I look in such a camera?  How fast should be the shutter speed? What other things I should look for? Singularity in Newton's gravitational law