2023-11-24 16:55:55 +01:00
<!doctype html>
< html lang = "en" dir = "ltr" class = "docs-wrapper plugin-docs plugin-id-c docs-version-current docs-doc-page docs-doc-id-bonuses/seminar-05-06" data-has-hydrated = "false" >
< head >
< meta charset = "UTF-8" >
2024-01-29 12:51:15 +01:00
< meta name = "generator" content = "Docusaurus v3.1.1" >
2023-11-24 16:55:55 +01:00
< title data-rh = "true" > 5th and 6th seminar | mf< / title > < meta data-rh = "true" name = "viewport" content = "width=device-width,initial-scale=1" > < meta data-rh = "true" name = "twitter:card" content = "summary_large_image" > < meta data-rh = "true" property = "og:url" content = "https://blog.mfocko.xyz/c/bonuses/seminar-05-06/" > < meta data-rh = "true" property = "og:locale" content = "en" > < meta data-rh = "true" name = "docusaurus_locale" content = "en" > < meta data-rh = "true" name = "docsearch:language" content = "en" > < meta data-rh = "true" name = "docusaurus_version" content = "current" > < meta data-rh = "true" name = "docusaurus_tag" content = "docs-c-current" > < meta data-rh = "true" name = "docsearch:version" content = "current" > < meta data-rh = "true" name = "docsearch:docusaurus_tag" content = "docs-c-current" > < meta data-rh = "true" property = "og:title" content = "5th and 6th seminar | mf" > < meta data-rh = "true" name = "description" content = "200IQ encryption .
">< meta data-rh = "true" property = "og:description" content = "200IQ encryption .
">< link data-rh = "true" rel = "icon" href = "/img/favicon.ico" > < link data-rh = "true" rel = "canonical" href = "https://blog.mfocko.xyz/c/bonuses/seminar-05-06/" > < link data-rh = "true" rel = "alternate" href = "https://blog.mfocko.xyz/c/bonuses/seminar-05-06/" hreflang = "en" > < link data-rh = "true" rel = "alternate" href = "https://blog.mfocko.xyz/c/bonuses/seminar-05-06/" hreflang = "x-default" > < link data-rh = "true" rel = "preconnect" href = "https://0VXRFPR4QF-dsn.algolia.net" crossorigin = "anonymous" > < link rel = "search" type = "application/opensearchdescription+xml" title = "mf" href = "/opensearch.xml" >
< link rel = "alternate" type = "application/rss+xml" href = "/blog/rss.xml" title = "mf RSS Feed" >
< link rel = "alternate" type = "application/atom+xml" href = "/blog/atom.xml" title = "mf Atom Feed" >
< link rel = "alternate" type = "application/json" href = "/blog/feed.json" title = "mf JSON Feed" >
2023-12-28 18:55:58 +01:00
< link rel = "stylesheet" href = "https://cdn.jsdelivr.net/npm/katex@0.13.24/dist/katex.min.css" integrity = "sha384-odtC+0UGzzFL/6PNoE8rX/SPcQDXBJ+uRepguP4QkPCm2LBxH3FA3y+fKSiJ+AmM" crossorigin = "anonymous" > < link rel = "stylesheet" href = "/assets/css/styles.e1ac7597.css" >
2024-02-04 17:41:39 +01:00
< script src = "/assets/js/runtime~main.2135d25d.js" defer = "defer" > < / script >
< script src = "/assets/js/main.6e9790c2.js" defer = "defer" > < / script >
2023-11-24 16:55:55 +01:00
< / head >
< body class = "navigation-with-keyboard" >
< script > ! function ( ) { function t ( t ) { document . documentElement . setAttribute ( "data-theme" , t ) } var e = function ( ) { try { return new URLSearchParams ( window . location . search ) . get ( "docusaurus-theme" ) } catch ( t ) { } } ( ) || function ( ) { try { return localStorage . getItem ( "theme" ) } catch ( t ) { } } ( ) ; t ( null !== e ? e : "light" ) } ( ) , function ( ) { try { const c = new URLSearchParams ( window . location . search ) . entries ( ) ; for ( var [ t , e ] of c ) if ( t . startsWith ( "docusaurus-data-" ) ) { var a = t . replace ( "docusaurus-data-" , "data-" ) ; document . documentElement . setAttribute ( a , e ) } } catch ( t ) { } } ( ) < / script > < div id = "__docusaurus" > < div role = "region" aria-label = "Skip to main content" > < a class = "skipToContent_fXgn" href = "#__docusaurus_skipToContent_fallback" > Skip to main content< / a > < / div > < nav aria-label = "Main" class = "navbar navbar--fixed-top" > < div class = "navbar__inner" > < div class = "navbar__items" > < button aria-label = "Toggle navigation bar" aria-expanded = "false" class = "navbar__toggle clean-btn" type = "button" > < svg width = "30" height = "30" viewBox = "0 0 30 30" aria-hidden = "true" > < path stroke = "currentColor" stroke-linecap = "round" stroke-miterlimit = "10" stroke-width = "2" d = "M4 7h22M4 15h22M4 23h22" > < / path > < / svg > < / button > < a class = "navbar__brand" href = "/" > < b class = "navbar__title text--truncate" > mf< / b > < / a > < div class = "navbar__item dropdown dropdown--hoverable" > < a href = "#" aria-haspopup = "true" aria-expanded = "false" role = "button" class = "navbar__link" > Additional FI MU materials< / a > < ul class = "dropdown__menu" > < li > < a class = "dropdown__link" href = "/algorithms/" > Algorithms< / a > < / li > < li > < a aria-current = "page" class = "dropdown__link dropdown__link--active" href = "/c/" > C< / a > < / li > < li > < a class = "dropdown__link" href = "/cpp/" > C++< / a > < / li > < / ul > < / div > < a class = "navbar__item navbar__link" href = "/contributions/" > Contributions< / a > < a class = "navbar__item navbar__link" href = "/talks/" > Talks< / a > < / div > < div class = "navbar__items navbar__items--right" > < a class = "navbar__item navbar__link" href = "/blog/" > Blog< / a > < div class = "toggle_vylO colorModeToggle_DEke" > < button class = "clean-btn toggleButton_gllP toggleButtonDisabled_aARS" type = "button" disabled = "" title = "Switch between dark and light mode (currently light mode)" aria-label = "Switch between dark and light mode (currently light mode)" aria-live = "polite" > < svg viewBox = "0 0 24 24" width = "24" height = "24" class = "lightToggleIcon_pyhR" > < path fill = "currentColor" d = "M12,9c1.65,0,3,1.35,3,3s-1.35,3-3,3s-3-1.35-3-3S10.35,9,12,9 M12,7c-2.76,0-5,2.24-5,5s2.24,5,5,5s5-2.24,5-5 S14.76,7,12,7L12,7z M2,13l2,0c0.55,0,1-0.45,1-1s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S1.45,13,2,13z M20,13l2,0c0.55,0,1-0.45,1-1 s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S19.45,13,20,13z M11,2v2c0,0.55,0.45,1,1,1s1-0.45,1-1V2c0-0.55-0.45-1-1-1S11,1.45,11,2z M11,20v2c0,0.55,0.45,1,1,1s1-0.45,1-1v-2c0-0.55-0.45-1-1-1C11.45,19,11,19.45,11,20z M5.99,4.58c-0.39-0.39-1.03-0.39-1.41,0 c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0s0.39-1.03,0-1.41L5.99,4.58z M18.36,16.95 c-0.39-0.39-1.03-0.39-1.41,0c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0c0.39-0.39,0.39-1.03,0-1.41 L18.36,16.95z M19.42,5.99c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06c-0.39,0.39-0.39,1.03,0,1.41 s1.03,0.39,1.41,0L19.42,5.99z M7.05,18.36c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06 c-0.39,0.39-0.39,1.03,0,1.41s1.03,0.39,1.41,0L7.05,18.36z" > < / path > < / svg > < svg viewBox = "0 0 24 24" width = "24" height = "24" class = "darkToggleIcon_wfgR" > < path fill = "currentColor" d = "M9.37,5.51C9.19,6.15,9.1,6.82,9.1,7.5c0,4.08,3.32,7.4,7.4,7.4c0.68,0,1.35-0.09,1.99-0.27C17.45,17.19,14.93,19,12,19 c-3.86,0-7-3.14-7-7C5,9.07,6.81,6.55,9.37,5.51z M12,3c-4.97,0-9,4.03-9,9s4.03,9,9,9s9-4.03,9-9c0-0.46-0.04-0.92-0.1-1.36 c-0.98,1.37-2.58,2.26-4.4,2.26c-2.98,0-5.4-2.42-5.4-5.4c0-1.81,0.89-3.42,2.26-4.4C12.92,3.04,12.46,3,12,3L12,3z" > < / path > < / svg > < / button > < / div > < div class = "navbarSearchContainer_Bca1" > < button type = "button" class = "DocSearch DocSearch-Button" aria-label = "Search" > < span class = "DocSearch-Button-Container" > < svg width = "20" height = "20" class = "DocSearch-Search-Icon" viewBox = "0 0 20 20" > < path d = "M14.386 14 . 386l4 . 0877 4 . 0877-4 . 0877-4 . 0877c-2 .
< p > < a href = "/files/c/bonuses/05-06.tar.gz" target = "_blank" rel = "noopener noreferrer" > Source< / a > < / p >
< h2 class = "anchor anchorWithStickyNavbar_LWe7" id = "introduction" > Introduction< a href = "#introduction" class = "hash-link" aria-label = "Direct link to Introduction" title = "Direct link to Introduction" > < / a > < / h2 >
< p > In this bonus you will implement few functions that will be used together for
implementing a very special cipher.< / p >
< h3 class = "anchor anchorWithStickyNavbar_LWe7" id = "task-no-1-reverse-05-k" > Task no. 1: Reverse (0.5 K₡)< a href = "#task-no-1-reverse-05-k" class = "hash-link" aria-label = "Direct link to Task no. 1: Reverse (0.5 K₡)" title = "Direct link to Task no. 1: Reverse (0.5 K₡)" > < / a > < / h3 >
< p > Write a function < code > char* reverse(const char* text)< / code > that returns copy of the input
string in reversed order (also uppercase).< / p >
< p > In case you are given < code > NULL< / code > , return < code > NULL< / code > .< / p >
< p > Example (more in tests):< / p >
2024-02-04 13:54:29 +01:00
< div class = "language-c codeBlockContainer_Ckt0 theme-code-block" style = "--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)" > < div class = "codeBlockContent_biex" > < pre tabindex = "0" class = "prism-code language-c codeBlock_bY9V thin-scrollbar" style = "background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)" > < code class = "codeBlockLines_e6Vv" > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > char< / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > *< / span > < span class = "token plain" > reversed < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > =< / span > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > reverse< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " Hello world!" < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" style = "display:inline-block" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > printf< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " %s\n" < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ,< / span > < span class = "token plain" > reversed< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token comment" style = "color:hsl(230, 4%, 64%)" > // " !DLROW OLLEH" < / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" style = "display:inline-block" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > if< / span > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token plain" > reversed < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > !=< / span > < span class = "token plain" > < / span > < span class = "token constant" style = "color:hsl(35, 99%, 36%)" > NULL< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > {< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > free< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token plain" > reversed< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > }< / span > < br > < / span > < / code > < / pre > < div class = "buttonGroup__atx" > < button type = "button" aria-label = "Copy code to clipboard" title = "Copy" class = "clean-btn" > < span class = "copyButtonIcons_eSgA" aria-hidden = "true" > < svg viewBox = "0 0 24 24" class = "copyButtonIcon_y97N" > < path fill = "currentColor" d = "M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z" > < / path > < / svg > < svg viewBox = "0 0 24 24" class = "copyButtonSuccessIcon_LjdS" > < path fill = "currentColo
2023-11-24 16:55:55 +01:00
< h3 class = "anchor anchorWithStickyNavbar_LWe7" id = "task-no-2-vigenère-05-k" > Task no. 2: Vigenère (0.5 K₡)< a href = "#task-no-2-vigenère-05-k" class = "hash-link" aria-label = "Direct link to Task no. 2: Vigenère (0.5 K₡)" title = "Direct link to Task no. 2: Vigenère (0.5 K₡)" > < / a > < / h3 >
< p > Vigenère cipher is similar to the Caesar cipher, but you also have a key that is
used for encrypting (or decrypting).< / p >
< p > Your task is to write two functions:< / p >
< ul >
< li > < code > char* vigenere_encrypt(const char* key, const char* text)< / code > for encrypting< / li >
< li > < code > char* vigenere_decrypt(const char* key, const char* text)< / code > for decrypting< / li >
< / ul >
< p > In both of those you should return uppercase characters.< / p >
< p > Meaning of the parameters you are given:< / p >
< ul >
< li > < code > key< / code > - String that represents key that is used for *crypting. It consists of
one word and can have only characters of the alphabet. Does not matter if they
are uppercase or lowercase.< / li >
< li > < code > text< / code > - String that is to be *crypted.< / li >
< / ul >
< p > Function returns address of the encrypted (or decrypted) string. Or < code > NULL< / code > in case
error occurs.< / p >
< p > Example:< / p >
2024-02-04 13:54:29 +01:00
< div class = "language-c codeBlockContainer_Ckt0 theme-code-block" style = "--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)" > < div class = "codeBlockContent_biex" > < pre tabindex = "0" class = "prism-code language-c codeBlock_bY9V thin-scrollbar" style = "background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)" > < code class = "codeBlockLines_e6Vv" > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > char< / span > < span class = "token plain" > < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > *< / span > < span class = "token plain" > encrypted < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > =< / span > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > vigenere_encrypt< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " CoMPuTeR" < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ,< / span > < span class = "token plain" > < / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " Hello world!" < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" style = "display:inline-block" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > printf< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " %s\n" < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ,< / span > < span class = "token plain" > encrypted< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token comment" style = "color:hsl(230, 4%, 64%)" > // " JSXAI PSINR!" < / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" style = "display:inline-block" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > if< / span > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token plain" > encrypted < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > !=< / span > < span class = "token plain" > < / span > < span class = "token constant" style = "color:hsl(35, 99%, 36%)" > NULL< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > {< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > free< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token plain" > encrypted< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > }< / span > < br > < / span > < / code > < / pre > < div class = "buttonGroup__atx" > < button type = "button" aria-label = "Copy code to clipboard" title = "Copy" class = "clean-btn" > < span class = "copyButtonIcons_eSgA" aria-hidden = "true" > < svg viewBox = "0 0 24 24" class = "copyButtonIcon_y97N" > < path fill = "currentColor" d = "M19,21H8V7H19M19,5H8A2,2 0 0 , 0 6 , 7V21A2 , 2 0 0 , 0 8 , 23H
2023-11-24 16:55:55 +01:00
< h4 class = "anchor anchorWithStickyNavbar_LWe7" id = "bonus-part-05-k" > Bonus part (0.5 K₡)< a href = "#bonus-part-05-k" class = "hash-link" aria-label = "Direct link to Bonus part (0.5 K₡)" title = "Direct link to Bonus part (0.5 K₡)" > < / a > < / h4 >
< p > If you can utilize helper function that would do both encrypting and decrypting,
you can gain 0.5 K₡.< / p >
< p > Usage of < code > true< / code > /< code > false< / code > to decide path in code is prohibited. It leads to merging
of both functions into one. Point of this part is to discover a way to do this
generically in such way that there are no separate paths for one or the other. One
function with no branching for both of them, parametrization is your friend :)< / p >
< h3 class = "anchor anchorWithStickyNavbar_LWe7" id = "task-no-3-bit-madness-05-k" > Task no. 3: Bit madness (0.5 K₡)< a href = "#task-no-3-bit-madness-05-k" class = "hash-link" aria-label = "Direct link to Task no. 3: Bit madness (0.5 K₡)" title = "Direct link to Task no. 3: Bit madness (0.5 K₡)" > < / a > < / h3 >
< p > This is a state of the art crypto. Please do not share :)< / p >
< p > For encrypting:< / p >
< ol >
< li > Split the character that is to be encrypted in halves (4 and 4 bits each).< / li >
< li > Bits in 1st half are to be split into pairs. Swap bits in those pairs.< / li >
< li > Then use the 4 bits that you created in the 2nd step for < code > XOR< / code > with the other
4 bits.< / li >
< / ol >
< p > This simple and ingenious principle will be illustrated on the following example.
String we want to encrypt is < code > Hello world!< / code > . We need to encrypt each letter separately,
so we will demonstrate on letter < code > H< / code > :< / p >
< ol >
< li >
< p > Letter < code > H< / code > is represented in ASCII as < code > 72< / code > .< / p >
< p > < code > 72< / code > represented in binary is: < code > 01001000< / code > . So first 4 bits are: < code > 0100< / code > and last
4 bits are < code > 1000< / code > .< / p >
< / li >
< li >
< p > First half of bits (< code > 0100< / code > ) consists of 2 pairs (< code > 01< / code > and < code > 00< / code > ) which we swap
(< code > 01 ~> 10< / code > and < code > 00 ~> 00< / code > ). That way we get < code > 1000< / code > .< / p >
< / li >
< li >
< p > That half is used for xor with the other 4 bits:< / p >
2024-02-04 13:54:29 +01:00
< div class = "codeBlockContainer_Ckt0 theme-code-block" style = "--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)" > < div class = "codeBlockContent_biex" > < pre tabindex = "0" class = "prism-code language-text codeBlock_bY9V thin-scrollbar" style = "background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)" > < code class = "codeBlockLines_e6Vv" > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > 1000 // second half< / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > XOR 1000 // first half after 2nd step< / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > --------< / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > 0000< / span > < br > < / span > < / code > < / pre > < div class = "buttonGroup__atx" > < button type = "button" aria-label = "Copy code to clipboard" title = "Copy" class = "clean-btn" > < span class = "copyButtonIcons_eSgA" aria-hidden = "true" > < svg viewBox = "0 0 24 24" class = "copyButtonIcon_y97N" > < path fill = "currentColor" d = "M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z" > < / path > < / svg > < svg viewBox = "0 0 24 24" class = "copyButtonSuccessIcon_LjdS" > < path fill = "currentColor" d = "M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z" > < / path > < / svg > < / span > < / button > < / div > < / div > < / div >
2023-11-24 16:55:55 +01:00
< / li >
< li >
< p > Now we combine both halves (first one is < code > 1000< / code > , which we got from the 2nd step
and second one is < code > 0000< / code > , which we got from the 3rd step) and get < code > 10000000< / code > ,
which is encrypted character < code > H< / code > using this method.< / p >
< / li >
< / ol >
< p > In case of decryption, reverse those steps.< / p >
< p > Your task is to implement functions:< / p >
< ul >
< li > < code > unsigned char* bit_encrypt(const char* text)< / code > < / li >
< li > < code > char* bit_decrypt(const unsigned char* text)< / code > < / li >
< / ul >
< p > Example:< / p >
2024-02-04 13:54:29 +01:00
< div class = "language-c codeBlockContainer_Ckt0 theme-code-block" style = "--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)" > < div class = "codeBlockContent_biex" > < pre tabindex = "0" class = "prism-code language-c codeBlock_bY9V thin-scrollbar" style = "background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)" > < code class = "codeBlockLines_e6Vv" > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > unsigned< / span > < span class = "token plain" > < / span > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > char< / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > *< / span > < span class = "token plain" > encrypted < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > =< / span > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > bit_encrypt< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " Hello world!" < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" style = "display:inline-block" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > for< / span > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token keyword" style = "color:hsl(301, 63%, 40%)" > int< / span > < span class = "token plain" > i < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > =< / span > < span class = "token plain" > < / span > < span class = "token number" style = "color:hsl(35, 99%, 36%)" > 0< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > i < / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > < < / span > < span class = "token plain" > < / span > < span class = "token number" style = "color:hsl(35, 99%, 36%)" > 12< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > i< / span > < span class = "token operator" style = "color:hsl(221, 87%, 60%)" > ++< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > {< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token function" style = "color:hsl(221, 87%, 60%)" > printf< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > (< / span > < span class = "token string" style = "color:hsl(119, 34%, 47%)" > " %x " < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ,< / span > < span class = "token plain" > encrypted< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > [< / span > < span class = "token plain" > i< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ]< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > )< / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > ;< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token comment" style = "color:hsl(230, 4%, 64%)" > //80 9c 95 95 96 11 bc 96 b9 95 9d 10< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > < span class = "token punctuation" style = "color:hsl(119, 34%, 47%)" > }< / span > < span class = "token plain" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" style = "display:inline-block" > < / span > < br > < / span > < span class = "token-line" style = "color:hsl(230, 8%, 24%)" > < span class = "token plain" > < / span > <
2023-11-24 16:55:55 +01:00
< h3 class = "anchor anchorWithStickyNavbar_LWe7" id = "task-no-4-all-combined-to-bmp-05-k" > Task no. 4: All combined to BMP (0.5 K₡)< a href = "#task-no-4-all-combined-to-bmp-05-k" class = "hash-link" aria-label = "Direct link to Task no. 4: All combined to BMP (0.5 K₡)" title = "Direct link to Task no. 4: All combined to BMP (0.5 K₡)" > < / a > < / h3 >
< p > Authors of the BMP cipher are non-disclosed :)< / p >
< p > Create pair of functions:< / p >
< ul >
< li > < code > unsigned char* bmp_encrypt(const char* key, const char* text)< / code > < / li >
< li > < code > char* bmp_decrypt(const char* key, const unsigned char* text)< / code > < / li >
< / ul >
< p > BMP cipher consists of following steps for encrypting:< / p >
< ol >
< li > Reverse the input string< / li >
< li > Use Vigenere on the string you got from step #1< / li >
< li > Use bit madness on the string you got from step #2< / li >
< / ol >
< p > For decrypting, reverse the steps.< / p >
< h2 class = "anchor anchorWithStickyNavbar_LWe7" id = "submitting" > Submitting< a href = "#submitting" class = "hash-link" aria-label = "Direct link to Submitting" title = "Direct link to Submitting" > < / a > < / h2 >
< p > In case you have any questions, feel free to reach out to me.< / p >
2024-02-04 17:41:39 +01:00
< hr > < / div > < footer class = "theme-doc-footer docusaurus-mt-lg" > < div class = "theme-doc-footer-edit-meta-row row" > < div class = "col" > < a href = "https://github.com/mfocko/blog/tree/main/c/bonuses/05-06.md" target = "_blank" rel = "noopener noreferrer" class = "theme-edit-this-page" > < svg fill = "currentColor" height = "20" width = "20" viewBox = "0 0 40 40" class = "iconEdit_Z9Sw" aria-hidden = "true" > < g > < path d = "m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z" > < / path > < / g > < / svg > Edit this page< / a > < / div > < div class = "col lastUpdated_vwxv" > < span class = "theme-last-updated" > Last updated<!-- --> on < b > < time datetime = "2024-02-04T12:58:19.000Z" > Feb 4, 2024< / time > < / b > < / span > < / div > < / div > < / footer > < / article > < nav class = "pagination-nav docusaurus-mt-lg" aria-label = "Docs pages" > < a class = "pagination-nav__link pagination-nav__link--prev" href = "/c/bonuses/seminar-04/" > < div class = "pagination-nav__sublabel" > Previous< / div > < div class = "pagination-nav__label" > 4th seminar< / div > < / a > < a class = "pagination-nav__link pagination-nav__link--next" href = "/c/bonuses/seminar-08/" > < div class = "pagination-nav__sublabel" > Next< / div > < div class = "pagination-nav__label" > 8th seminar< / div > < / a > < / nav > < / div > < / div > < div class = "col col--3" > < div class = "tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop" > < ul class = "table-of-contents table-of-contents__left-border" > < li > < a href = "#introduction" class = "table-of-contents__link toc-highlight" > Introduction< / a > < ul > < li > < a href = "#task-no-1-reverse-05-k" class = "table-of-contents__link toc-highlight" > Task no. 1: Reverse (0.5 K₡)< / a > < / li > < li > < a href = "#task-no-2-vigenère-05-k" class = "table-of-contents__link toc-highlight" > Task no. 2: Vigenère (0.5 K₡)< / a > < / li > < li > < a href = "#task-no-3-bit-madness-05-k" class = "table-of-contents__link toc-highlight" > Task no. 3: Bit madness (0.5 K₡)< / a > < / li > < li > < a href = "#task-no-4-all-combined-to-bmp-05-k" class = "table-of-contents__link toc-highlight" > Task no. 4: All combined to BMP (0.5 K₡)< / a > < / li > < / ul > < / li > < li > < a href = "#submitting" class = "table-of-contents__link toc-highlight" > Submitting< / a > < / li > < / ul > < / div > < / div > < / div > < / div > < / main > < / div > < / div > < / div > < footer class = "footer footer--dark" > < div class = "container container-fluid" > < div class = "row footer__links" > < div class = "col footer__col" > < div class = "footer__title" > Git< / div > < ul class = "footer__items clean-list" > < li class = "footer__item" > < a href = "https://github.com/mfocko" target = "_blank" rel = "noopener noreferrer" class = "footer__link-item" > GitHub< svg width = "13.5" height = "13.5" aria-hidden = "true" viewBox = "0 0 24 24" class = "iconExternalLink_nPIU" > < path fill = "currentColor" d = "M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z" > < / path > < / svg > < / a > < / li > < li class = "footer__item" > < a href = "https://gitlab.com/mfocko" target = "_blank" rel = "noopener noreferrer" class = "footer__link-item" > GitLab< svg width = "13.5" height = "13.5" aria-hidden = "true" viewBox = "0 0 24 24" class = "iconExternalLink_nPIU" > < path fill = "currentColor" d = "M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z" > < / path > < / svg > < / a > < / li > < li class = "footer__item" > < a href = "https://git.mfocko.xyz/mfocko" target = "_blank" rel = "noopener noreferrer" class = "footer__link-item" > Gitea (self-hosted)< svg width = "13.5" height = "13.5" aria-hidden = "true" viewBox = "0 0 24 24" class = "iconExternalLink_nPIU" > < path fill = "currentColor" d = "M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z" > < / path > < / svg > < / a > < / li > < / ul > < / div > < div class = "col footer__col" > < div class = "footer__title" > Social #1< / div > < ul class = "footer__items clean-list" > < li class = "footer__item" > < a href = "https://www.linkedin.com/in/mfocko/" target = "_blank" rel = "noopener noreferrer" class = "footer__link-item" > LinkedIn< svg width = "13.5" height = "13.5" aria-hidden = "true" viewBox = "0 0 24 24" class = "iconExternalLink_nPIU" > < path fill = "currentColor" d = "M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10 . 988l4 . 035 4-6 . 977 7 . 07 2 . 828 2 . 828 6 . 977-7 . 07 4 . 125 4
2023-11-24 16:55:55 +01:00
< / body >
< / html >
