int num1 = 8;   //okay int *pointer;   //okay *pointer = &amp;num1;   //NOT okay, compiler says (Error:a value of type int* cannot be                     //assigned to an entity of type "int")  int num2 = 8;   //okay int *pointer = &amp;num2;   //okay   I am confused why the first part gives an error and the 2nd part doesnt, they look the same to me
Why are pointers such a leading factor of confusion for many new, and even old, college level students in C or C++?  Are there any tools or thought processes that helped you understand how pointers work at the variable, function, and beyond level?  What are some good practice things that can be done to bring somebody to the level of, "Ah-hah, I got it," without getting them bogged down in the overall concept? Basically, drill like scenarios.
Execute bash script from URL Two icons on Unity Launcher on non-standard application launch I have an application which doesn't come from any Ubuntu repo (neither official, nor PPA) but available as tgz and supposed to be unpacked and ready to use. To be precise it is .   The problem is the  application when launched shows its own icon in Unity Launcher. After making a custom .desktop file and placing shortcut onto Unity Launcher (by dragging from the dash) and launching it I see two icons - one placed by me and another one with real application.  This is the .desktop contents:  [Desktop Entry] Version=1.0 Type=Application Terminal=false Exec=/opt/LightTable/LightTable Name=Light Table Icon=/opt/LightTable/core/img/lticon.png   One more thing. The /opt/LightTable/LightTable is bash script file and eventually /opt/LightTable/ltbin is being launched. I think this is the problem but have no idea how to fix the problem. What is Change Detection and performing such analysis with open source tools? How to specify font size less than 10pt (or more than 12pt)? What prevents this magnetic perpetuum mobile from working? Find all roots of $\,x^2\!\equiv x\pmod{\!900}$, i.e all idempotents in $\Bbb Z_{900}$ I need the idempotent elements of $Z_{900}$ $2^2\cdot 3^2\cdot 5^2=900$ Of course there's $$0 \pmod 4 \\ 0 \pmod 9 \\ 0 \pmod {25} \\ $$ and $$ 1 \pmod 4 \\ 1 \pmod 9 \\ 1 \pmod {25} \\ $$ I found the answers by making a C++ program to test all numbers, but I don't know how to quick solve on paper. This is the output of the program $(0, 0, 0) \rightarrow 0 \\ (1, 1, 1) \rightarrow 1 \\ (0, 0, 1) \rightarrow 576 \\ (0, 1, 0) \rightarrow 100 \\ (1, 0, 0) \rightarrow 225 \\ (1, 1, 0) \rightarrow 325 \\ (0, 1, 1) \rightarrow 676 \\ (1, 0, 1) \rightarrow 801 \\$ How could I detect (preferably with Python) duplicate MP3 files that can be encoded with different bitrates (but they are the same song) and ID3 tags that can be incorrect?  I know I can do an  checksum of the files content but that won't work for different bitrates. And I don't know if ID3 tags have influence in generating the MD5 checksum. Should I re-encode MP3 files that have a different bitrate and then I can do the checksum? What do you recommend? Recording iPad screen using QuickTime I need to record a demo on my iPad's screen where I narrate what's going on but I also want the sounds from the iPad to be in the video. It seems that choosing the Mac Built-in Mic option causes only my voice to be in the video while choosing the iPad Mic option cause only the sounds from the iPad to be in the video. What can I do to put both in the video? The particle number on my settings appear in gray, I don't think i'm able to change the number even thought i need it, how can i make it white again? Evaluation of $\displaystyle \int_{0}^{1}\frac{x\ln (x)}{\sqrt{1-x^2}}dx$   $\bf{My\; Try::}$ Let $\displaystyle I = \int_{0}^{1}\frac{x\ln x}{\sqrt{1-x^2}}dx\;,$ Put $x=\cos \phi\;,$ Then $dx = -\sin \phi d\phi$  and Changing Limit, We get  $$\displaystyle I = -\int_{\frac{\pi}{2}}^{0}\cos \phi \cdot \ln(\cos \phi )d\phi = \int_{0}^{\frac{\pi}{2}} \ln(\cos \phi)\cdot \cos \phi d\phi$$  Now Using Integration by parts, We get  $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\frac{\sin^2 \phi}{\cos \phi}d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\frac{(1-\cos^2 \phi)}{\cos \phi}d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\sec \phi d\phi-\int_{0}^{\frac{\pi}{2}}\cos \phi d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\left[\ln\left|\sec \phi+\tan \phi\right|\right]_{0}^{\frac{\pi}{2}}-\left[\sin \phi\right]_{0}^{\frac{\pi}{2}}$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\left[\ln\left|\sec \phi+\tan \phi\right|\right]_{0}^{\frac{\pi}{2}}-1$$  Now How can I solve after that, Help Required, Thanks Getting GIF and/or moving images into a LaTeX presentation I'm very new to presentations in LaTeX (I've been using PowerPoint for years but have finally converted). I am wondering how to get a GIF into a section. If need be, I can convert a GIF into lots of pictures and have them overlay to give the impression of movement. Creating Workflow -> Error Daily reputation cap doesn't account for reputation * loss* due to bounty awarded? There are many Q&amp;A's around this and the best explanation of daily cap model is from this answer that uses . It is an old answer but gives a good understanding.   My confusion is in applying this model to my situation yesterday.    On 31/12/2019, I awarded a bounty to , since it became eligible for bounty (2 days after posting it). Subsequently, I got more upvotes (including one accept) which exceeded the daily cap of 200. I am confused about this-loss of reputation due to bounty awarded by me preceeded subsequent gain of reputation so going by the bucket analogy, I should have my rep adjusted accordingly and those 6 up votes (at the bottom of table) should have been credited (rep should have been 177 instead of 117),  /reputation shows this   2 219845 (10)  1 219884 (2)  2 170717 (10)  2 219621 (10)  2 219845 (10) 2 219845 (10) 2 218537 (10)  2 219845 (10)  2 219892 (10)  2 219845 (10) 8 219821 (-100)  2 219845 (10)  2 219621 (10)  2 219845 (10)  2 219821 (10)  2 219845 (10)  2 219845 (10)  2 219845 (10)  2 219912 (10)  1 219912 (15)  2 219845 (10)  2 219845 (10)  2 219892 [10]  2 219845 [0]  2 219621 [0]  2 219845 [0]  2 219845 [0]  2 219845 [0]  2 219845 [0]  -- 2019-12-31 rep +117 = 27089 --   It is not the 6 votes I am bothered about, it is more about trying to correct my understanding  or have I stumbled upon an anomaly? Should I really have been awarded mortarboard on a Per-site meta? Are PHP short tags acceptable to use? Here's the information :     There are four different pairs of   opening and closing tags which can be   used in PHP. Two of those, &lt;?php ?&gt;   and &lt;script language="php"&gt; &lt;/script&gt;,   are always available. The other two   are short tags and ASP style tags, and   can be turned on and off from the   php.ini configuration file. As such,   while some people find short tags and   ASP style tags convenient, they are   less portable, and generally not   recommended.   In my experience most servers do have short tags enabled. Typing  &lt;?=   is far more convenient than typing  &lt;?php echo    The programmers convenience is an important factor, so why are they not recommended? Sentient Bomb in a city on the moon? I would like to know the title of the short story that I believe takes place on the moon.  The setting is a mall or some other very public location and the main character is a police officer.  She needs to talk a sentient bomb out of exploding.  I know there was the John Carpenter film "Dark Star" with a similar plot line but I'm trying to identify the short story and the author. Both  (if you take a list of values, the distribution of the most significant digit is rougly proportional to the logarithm of the digit) and  (given a corpus of natural language utterances, the frequency of any word is roughly inversely proportional to its rank in the frequency table) are not theorems in a mathematical sense, but they work quite good in the real life.   Does anyone have an idea why this happens?  (see also ) How can I make an overset symbol at the same size and height as \bar except with a different symbol? Apologies for the cryptic title, but I was not sure how best to phrase the question in one sentence. I am essentially trying the create a vector symbol with \rightharpoonup as the top instead of the arrow.  The output to the following code will feature an overset harpoon over x, next to a simple \bar{x}. Observe that on the left, the top symbol is significantly higher and bigger than on the right one.  \documentclass{article}  \usepackage{amsmath,amsfonts,amsthm,amssymb}  \newcommand{\vect}[1]{\overset{\rightharpoonup}{#1}}  \begin{document} $$ \vect{x} \quad \bar{x} $$ \end{document}   I would like to create something that looks in every way like the right hand symbol, except using something that looks like \rightharpoonup at the top.  If this command sequence already exists in LaTeX, please use that as an answer, because I have searched for and failed to find it so far. How to check who owns the Slack's workspace? I'd like to check who owns (or at least some kind of public profile page) some workspace based on its subdomain (e.g. xyz.slack.com).  Is it possible? What is the difference between "speaking" and "talking"? It seems more politically correct to say that someone is speaking rather than talking.  What is the definitive difference between these terms?