I am practicing for USACO Bronze and came across the Fence Painting Problem from USACO 2015 December. My code is working on Eclipse and everything is fine but when the USACO website tests it, I get this error: Error: Could not find or load main class Paint Caused by: java.lang.NoClassDefFoundError: introduction/Paint (wrong name: Paint) I have no idea what is causing this. This is my code: package introduction;  import java.io.*; import java.util.*; public class Paint {     public static void main(String args[]) throws IOException {         PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(&quot;paint.out&quot;)));                  Scanner keyboard = new Scanner(new FileReader(&quot;paint.in&quot;));                  int a = keyboard.nextInt();         int b = keyboard.nextInt();         int c = keyboard.nextInt();         int d = keyboard.nextInt();                  if (a&lt;c &amp;&amp; b==d) {             out.println(b-a);         }         if (a&lt;c &amp;&amp; b&lt;d) {             out.println(d-a);         }         if (a&lt;c &amp;&amp; b&gt;d) {             out.println(b-a);         }         if (a&gt;c &amp;&amp; b==d) {             out.println(d-c);         }         if (a&gt;c &amp;&amp; b&lt;d) {             out.println(d-c);         }         if (a&gt;c &amp;&amp; b&gt;d) {             out.println(b-c);         }         if (a==c &amp;&amp; b==d) {             out.println(b-a);         }         if (a==c &amp;&amp; b&lt;d) {             out.println(d-c);         }         if (a==c &amp;&amp; b&gt;d) {             out.println(b-a);         }         out.close();     } }  Please help me. Thank you!
I am getting a NoClassDefFoundError when I run my Java application.  What is typically the cause of this?
Show that the operator norm is submultiplicative We had in our lecture on numerical analysis the following: Let $\mathrm{Lin}(X,Y)$ be the set of all linear maps $X\rightarrow Y$. Let $A\in\mathrm{Lin}(\mathbb R^l,\mathbb R^n)$ and $B\in\mathrm{Lin}(\mathbb R^n,\mathbb R^m)$ and $\|C\|_{op}:=\max_{\|x\|\leq1}\|C(x)\|$. Then our lecturer followed $\|A\circ B\|_{op}\leq\|A\|_{op}\cdot\|B\|_{op}$. So he didn't prove it and so I've tried it by my own. My attempt: $$\begin{aligned} \|A\circ B\|_{\mathrm{op}} &amp;= \max_{\|x\| &lt; 1}\|(A \circ B)(x)\| \\ &amp; \leq \max_{\|x\| &lt; 1} \|A\|_{\mathrm{op}} \|B(x)\| \\ &amp;= \|A\|_{\mathrm{op}} \max_{\|x\|\leq1}\|B(x)\|\\ &amp;= \|A\|_{\mathrm{op}}\|B\|_{\mathrm{op}} \end{aligned}$$ But this seems too easy. I am really interested in a nice proof so anybody could help? Thanks a lot! Functional equations leading to sine and cosine Can two PS4s log in to the same PSN account? Both myself and my boyfriend have PS4s.  Can I just get a single PSN account and sign both consoles into the same account, or do I need to get two separate accounts? how to convert System::String to const char*? Why is the Sun approximated as a black body at ~ 5800 K? What exactly is an environment variable? I know that VARIABLE=value creates an environment variable, and export VARIABLE=value makes it available to processes created by the current shell. env shows the current environment variables, but where do they live? What comprises an environment variable (or an environment, for that matter)? PHP replacing special characters like à->a, è->e Who are the Steam Mascots? So with the Steam Summer Sale in full swing, I've finally taken notice of the Steam Mascots.  Judging by the latest background, the black one, at least, has a name: Cyl.  Do the other two have names as well? Are there only these three?   What's their story? Are users notified when their questions are reopened? Do users get notified when their question is reopened? I know there are no notifications , and that makes sense because 1) you assume the user is paying attention to their open, unanswered question, and they'll probably notice it's been put on hold and 2) it follows with the SE policy of (in general) not sending notifications for negative events.  However a reopening is a good thing, and once a question is closed it becomes less likely that the OP will be coming back to check on it often (so they might not notice the reopening otherwise). If there are not reopen notifications, why not? Or can we add them? Reading Excel files from C# Is there a free or open source library to read Excel files (.xls) directly from a C# program?   It does not need to be too fancy, just to select a worksheet and read the data as strings. So far, I've been using Export to Unicode text function of Excel, and parsing the resulting (tab-delimited) file, but I'd like to eliminate the manual step. What does the "static" modifier after "import" mean? When used like this:  import static com.showboy.Myclass;  public class Anotherclass{}   what's the difference between import static com.showboy.Myclass and import com.showboy.Myclass? In bash, how do I escape an exclamation mark? I want to do something like bzr commit -m "It works!". I can sort of escape the exclamation mark by doing bzr commit -m "It works\!". However, then my commit message includes the backslash. How do I escape the exclamation mark, while still ignoring the backslash? n-dimensional vector space isomorphic to the n-th product of a field as abelian groups Let $V$ be a finite dimensional vector space (of dimension n) over a field $F$. I need to show that $V$ is isomorphic to $F^n$ as abelian groups. However, I don't really understand what does "isomorphic as abelian groups" mean, my (poor) attempt to solve this was:  Let $f:V\to F^n$, $f((v_1,v_2,\ldots,v_n)):=v_1+\ldots+v_n$, clearly $f$ is a group homomorphism, but it is not biyective since, for example, in the case where $dim(V)=2$ and $F=\mathbb{R}$ we have $f((2,-2))=0=f((3,-3))$, I've also tried it by defining $f$ to be the product of a vector's entries but obviously it didn't work so I'm stuck!   I think this should be an easy problem but since I don't quite understand it, it's giving me problems. Thank you for your help. By default after a new user signs up, a redirect to the home page happens.  But in such case I want to redirect such user to another page like node/35.  In this node/35 I then want to display some content. Is there a phrase that means sleeping with someone without sex? Class moderncv moving footer I am using documentclass moderncv to style my resume, and I'd like to put the information that normally goes at the bottom of the document, such as phone number and email, to the space next to the name aligned on the left of the document. I'm a beginnner user, so I'd love to get some enlightenment on this.  \documentclass[11pt,letterpaper,sans]{moderncv}  % moderncv themes \moderncvstyle{casual} \moderncvcolor{blue} \usepackage[scale=0.75]{geometry}  % personal data \firstname{John} \familyname{Doe} \mobile{+1~(234)~567~890}  % content  \begin{document} \makecvtitle \pagestyle{empty}  \section{Education} \cventry{1998-2007}{Degree}{Institution}{City}{\textit{Grade}}{Description}   \section{Computer skills}  \thispagestyle{plain} \end{document}    Simply put, I want to move \mobile from the bottom to the top left. If a prime divides a product then it must divide a factor of the product [Euclid's Lemma] We have $q, p$ prime and $tq = (p-1)(p+1)$ for some positive integer $t$. The book I'm reading says that because $q$ is prime, it divides $p-1$ or $p+1$.   Question: Why exactly does it matter that $q$ is prime here? Can I choose not to defend against an attack? Playing D&amp;D4e, I have a situation in mind where a character could reasonably WANT to get hit with a normally harmful attack. Is there anything in the rules allowing the character to purposefully take the hit, not even bothering to attempt to defend or dodge out of the way of it?  For example, a dragonborn character makes a breath attack that includes an ally in its blast. The dragonborn has the Nusemnee's Atonement feat, which allows a player whose AOE damages an ally to take the ally's damage instead. This can be paired with a dragonborn feat that recharges your racial dragonbreath power when you take damage of the type it deals. This combination lets the dragonborn recharge their dragonbreath as long as they hit an ally with it. Normally you'd want your ally to at least have a chance to dodge your AOE first, but in this combo, it's best if they can allow themselves to get hit!  Can the ally choose not to defend against the attack, purposefully taking the hit, knowing that the character making the attack will take the damage in his place? So people have had similar problems showing colors on .ply files  and   but I don't think this is the same case.  I've exported a .ply file from a program called paraview with color info on it.  I've uploaded the file  and as you can see, the color info came with it.  But for whatever reason when I import it into blender and go look for the per-vertex color info where I would expect to find it, its empty:   Am I doing something wrong?  It seems like there had been a problem with impo but this is 2.81.  I would assume it was fixed? Review Queues and Ignored Tags Steps to Recreate:   Have enough rep to use some of the review queues. Ignore a popular tag. Go to your profile-> prefs-> check 'hide ignored tags'. Open a review queue.   You will get questions from your ignored tag(s) in the review queue.  Personally, I ignored a tag on Movies.SE (and Scifi.SE) for a film that is out elsewhere in the world, but not locally.  It's a simple way to avoid being exposed to spoilers.  I then load up the First Posts review queue on Movies.SE, and I get an answer to a question about the end of the film.  Can the review queues be altered to skip posts on your ignored tags when you have the 'hide ignored tags' option enabled?