A square $10 X10$ is completed with numbers from 1 to 100 such that 2 consecutive numbers are in neighbor little squares.  Show that that on a line or a column there exists more than 2 perfect square.(A perfect square is a positive integer of the form $k^2$)  Looks that there are not too much ways to complete a such square.
Let   consider   a  square $10\times 10$   and  write  in  the   every   unit  square    the   numbers   from  $1$  to  $100$   such  that   every  two   consecutive  numbers  are  in   squares   which  has  a  common edge.  Then  there  are  two  perfect  squares   on  the  same line  or  column. Can  you   give  me  an  hint? How  to  start?
Do I have to use “do” in any “wh-” question? What did you say?  What you said?   What did you wear? What you wore?    Where did you go? Where you go?    I know that sometimes in English, people do not use “do” in “wh-” questions. I have heard somewhere that people do not use “do” when the answer is a proper noun or a unique thing. Am I right? I'm trying to split a string up into words and punctuation, adding the punctuation to the list produced by the split.  For instance:  &gt;&gt;&gt; c = "help, me" &gt;&gt;&gt; print c.split() ['help,', 'me']   What I really want the list to look like is:  ['help', ',', 'me']   So, I want the string split at whitespace with the punctuation split from the words.  I've tried to parse the string first and then run the split:  &gt;&gt;&gt; for character in c: ...     if character in ".,;!?": ...             outputCharacter = " %s" % character ...     else: ...             outputCharacter = character ...     separatedPunctuation += outputCharacter &gt;&gt;&gt; print separatedPunctuation help , me &gt;&gt;&gt; print separatedPunctuation.split() ['help', ',', 'me']   This produces the result I want, but is painfully slow on large files.  Is there a way to do this more efficiently? How do I open the user folder of a hard drive that I transfered? My Windows 10 notebook died but fortunately I was able to rescue the hard drive and put it into another PC.   Unfortunately, the other PC can't open the C/Users/Joe folder. What do I have to do to open the folder? I'm running macOS Catalina 10.15.4 on a 2018 MacBook Pro 15", which has the T2 chip (if anything else is relevant, let me know and I'll update the question.)  I'm a developer and I'm in the process of writing and debugging a C command-line utility that's supposed to take a few miliseconds to run and exit.  My internet connection went down while I was coding (WiFi was still connected, but my ISP was down), and afterwards I noticed that, after compiling the app, the first time I ran it, it took a few seconds to run rather than the expected fraction of a second.  I turned off WiFi (so there was no active network connection), compiled my app again, and ran it -- this time it ran as quick as I would expect.  Turn on WiFi, compile and run again, first run of the app takes longer than expected.  Maybe I'm paranoid, but it sure sounds like macOS is trying to ask Apple's servers for blessing to run my app. Is this the case, or could there be another explanation? If it's indeed the case, can anyone link to an article explaining what's going on under the hood?  UPDATE: as requested, here are timings for an average of three runs of the following command, under different conditions:  touch file.c &amp;&amp; make &amp;&amp; time ./file &amp;&amp; time ./file  The first measurement is the average time for running file for the first time after compilation (the third command in the chain). The second measurement is the average time for running file for the second time after compilation (the fourth command in the chain).  WiFi on, with internet: 347 ms/3 ms.  WiFi on, without internet: 5024 ms/3 ms.  All network connections offline: 24 ms/2 ms. Why $SU(3)$ and not $U(3)$? Both options affect colors in a similar way, but I can't figure out the difference. I tried to get the number of available brew packages by running  brew search | wc -l   but I don't know how accurate this really is. What do I need to take into account to get a more correct number?  PS: macports lists 19,889 packages online #1115 - Unknown character set: 'utf8mb4' When I Import Mysql from local server to web ser it is showng me error 1115 - Unknown character set: 'utf8mb4' in Creating wordpress wp_comment table CREATE TABLE IF NOT EXISTS  `wp_commentmeta` ( // // ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4 AUTO_INCREMENT =1;  #1115 - Unknown character set: 'utf8mb4'  My mysql version is Version information: 4.0.4, latest stable version: 4.4.10 (local version)  Version information: 4.0.10.7, latest stable version: 4.4.10( server version)  Please help me to solve out the error What are the current travel restrictions on individuals entering the United States from regions affected by Covid-19? This community wiki explains the current restrictions by the United States of America on the entry of individuals who may pose a risk of transmission of the SARS-Cov2, the virus which causes the Covid-19 disease. Why do RAW images look worse than JPEGs in editing programs? I've found that when you load a RAW image into an editing program such as Lightroom/Aperture, the image is usually worse than if you just took the image as JPEG. Now I understand that the camera does some magic during the JPEG conversion. But I'm trying to understand what that "magic" is.   If I'm looking to implement that "magic" myself on the desktop, what kind of settings should I be trying? I find that the RAW files have more extreme contrast. The dark areas for example are way darker than JPEG. Why is this? And what is the best way to fix this? Auto delete spam email from a domain in Gmail How does Dijkstra's Algorithm and A-Star compare? What is a more efficient way to draw this tree? I have drawn the following tree in TikZ. What I don't like about it is   that I have to manually adjust the sibling distance for each level; and the syntax is too cumbersome.   It has been suggested to me by @percusse and @AlanMunn that using tikz-qtree and/or forest may be a more efficient way to produce the same result. But I don't have experience in using either package.   It would be nice if someone can reproduce my example using either of these packages, so that I can have quick example to learn from instead of reading a 150-page manual trying to find an answer.    \documentclass{standalone} \usepackage{tikz} \usepackage{amsmath}  \begin{document}  \tikzset{   % Two node styles for game trees: solid and hollow   solid node/.style={circle,draw,inner sep=1.2,fill=black},   hollow node/.style={circle,draw,inner sep=1.2}, }  % macro for entering payoffs \newcommand\payoff[1]{   $\begin{pmatrix} #1 \end{pmatrix}$ }  \begin{tikzpicture}[font=\footnotesize]   \tikzset{     level 1/.style={level distance=15mm,sibling distance=65mm},     level 2/.style={level distance=15mm,sibling distance=30mm},     level 3/.style={level distance=15mm,sibling distance=15mm},     level 4/.style={level distance=15mm,sibling distance=10mm},   }    \node[hollow node,label=above:{Nature}]{}     child{node[solid node,label=left:{P1}]{}       child{node(l1)[solid node]{}         child{node[solid node,label=below:{\payoff{1\\-1}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[right]{R}}         edge from parent node[left]{U}       }       child{node(l2)[solid node]{}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{2\\-2}}]{}edge from parent node[right]{R}}         edge from parent node[right]{D}       }       edge from parent node[left,xshift=-10]{A}     }     child{node[solid node,label=right:{P1}]{}       child{node(r1)[solid node]{}         child{node[solid node,label=below:{\payoff{-2\\2}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[right]{R}}         edge from parent node[left]{U}       }       child{node(r2)[solid node]{}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{-1\\1}}]{}edge from parent node[right]{R}}         edge from parent node[right]{D}       }       edge from parent node[right,xshift=10]{B}     }   ;    \draw[dashed](l1)--(l2)--node[midway,above]{P2}(r1)--(r2); \end{tikzpicture}  \end{document} Implementing the decorator pattern in Python The question I want to ask is related to the answer of this question:  .   My aim is to separate my bibliography into two parts : one part for a personnal bibliography, and a second one for the regular bibliography.  To do that, I use the technique of the post I cited :  \documentclass{article} \usepackage[T1]{fontenc} \usepackage[french]{babel} \usepackage[style=alphabetic,maxnames=6,natbib=true]{biblatex} \bibliography{biblatex-examples}  % Variants of each could be added \newcommand{\firstname}{Donald~E.} \newcommand{\lastname}{Knuth}  \DeclareBibliographyCategory{byname}  \DeclareIndexNameFormat{byname}{% Test could be refined   \ifboolexpr{ test {\ifdefstring{\lastname}{#1}}            and test {\ifdefstring{\firstname}{#3}}               } {\addtocategory{byname}{\thefield{entrykey}}} {}}  \AtDataInput{%   \indexnames[byname]{author}}  \begin{document}  \section{Knuth's books}  \begin{refsection}  \nocite{*}  \printbibliography[category=byname,heading=none]  \end{refsection}  \section{Not Knuth's books}  \printbibliography[notcategory=byname,heading=none] \end{document}   The problem is that only the second bibliography appears, and when I remove the refsection, then all the bibtex entries of my input files are printed, separated as they should.  EDIT: the aim is to have all publications (even the ones not cited) by author knuth in the first section and all the other cited publications in the second one. Show that, in any finite graph with at least two vertices, there must be two vertices with the same degree.  HINTS ONLY! How to run scripts on start up? Negation in English Are we close to a pure DC (or hybrid) household? This is a philosophical question. Over the last few years, many of the household devices, particularly those that are more mobile and etc are DC devices. Are we at some point where a DC household may become a possibility and Edisons dream might come true??  The array of DC devices    Internet stuff - routers, modems Most complex computer electronics - Desktops, laptops, NAS, phones, tablets, gaming consoles, etc Lighting - LED More that I cant think of or perhaps know which also convert AC -> DC   Problems with AC     Each device needs its own power supply ( AC-> DC power brick). This is a) Unpleasant to look at and deal with, and b) a costly point of failure.  Each power brick may or may not be optimized, as far as power conversion goes.   Alternative - A central (or a few ) high capacity power adapter which converts the AC into a DC power grid for the house which can then be tapped directly by the various devices. This eliminates the need for the power brick, and hopefully the central power adapter is of state of the art, and can be upgraded seperately from the devices, as needed.  Need standardization of:   Device voltage. Currently devices use 5/ 9 / 12 or others I may not be aware of, for this idea to work they need to work with one particular one, unless switching between voltages is cheap enough, or multiple DC lines are provided. Power socket input. Each device appears to have its own input socket type, this should standardize if the power supply cable should be comoditized, perhaps USB - C will play a part here. Clickable Table Footnote I'm trying to have some clickable footnotes within tables. I tried using \footnote{}, it does create a link but there's no footnote text associated with it. \footnotemark[number] along with \footnotetext[]{} does create a fotenote but then there's no hyperlink. (I would like to make it clear that I'm trying to have footnotes at the bottom of the page and not footnotes within the table.)  Here's a small code snippet:  \documentclass{report}  \usepackage{hyperref} \begin{document}  \begin{table}[h!]     \centering     \begin{tabular}{|r|r|r|}         \hline         A\footnote{Test!} &amp; B\footnotemark[4] &amp; C\footnotemark[5]\\         \hline         123 &amp; Tim &amp; Jane\\         \hline         456 &amp; Tom &amp; Jung\\         \hline     \end{tabular}     \caption{A table} \end{table}  This is a clickable footnote\footnote{You clicked me!}.  \footnotetext[4]{This is B} \footnotetext[5]{This is C}  \end{document}