From ec94b4ae3a5bfae451210fe0329c0dbd7bccbda2 Mon Sep 17 00:00:00 2001 From: Jan Meyer Date: Thu, 16 Apr 2026 11:48:52 +0200 Subject: [PATCH] vault backup: 2026-04-16 11:48:52 --- .gitignore | 2 + .obsidian/workspace.json | 49 +++++-------- 00 Inbox/29605546 - 29593852 - Strings.md | 71 +++++++++++++++++++ 00 Inbox/29605547 - 29605397 - OOP.md | 18 +++++ 00 Inbox/29605548 - 29605397 - OOP.md | 18 +++++ .../02 - SoSe 2026/OOP/29605321 - Classes.md | 2 +- .../02 - SoSe 2026/OOP/29605397 - OOP.md | 6 -- 40 Extras/OOP_Lecture | 1 + 8 files changed, 128 insertions(+), 39 deletions(-) create mode 100644 00 Inbox/29605546 - 29593852 - Strings.md create mode 100644 00 Inbox/29605547 - 29605397 - OOP.md create mode 100644 00 Inbox/29605548 - 29605397 - OOP.md delete mode 100644 10 Courses/02 - SoSe 2026/OOP/29605397 - OOP.md create mode 160000 40 Extras/OOP_Lecture diff --git a/.gitignore b/.gitignore index 57bd0b6..d7f288a 100644 --- a/.gitignore +++ b/.gitignore @@ -1 +1,3 @@ .trash/ +.obsidian/snippets/ +.obsidian/workspace.json diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json index c5a1833..03d0cf3 100644 --- a/.obsidian/workspace.json +++ b/.obsidian/workspace.json @@ -11,14 +11,10 @@ "id": "140d404d9b2faf63", "type": "leaf", "state": { - "type": "markdown", - "state": { - "file": "conflict-files-obsidian-git.md", - "mode": "source", - "source": false - }, + "type": "empty", + "state": {}, "icon": "lucide-file", - "title": "29593852 - Strings" + "title": "New tab" } } ] @@ -184,26 +180,29 @@ }, "active": "7a0e7b37bd89861d", "lastOpenFiles": [ - "10 Courses/02 - SoSe 2026/OOP/29605397 - OOP.md", + "00 Inbox/29605548 - 29605397 - OOP.md", + "00 Inbox/29605547 - 29605397 - OOP.md", "10 Courses/02 - SoSe 2026/OOP/29605321 - Classes.md", - "40 Extras/OOP_Lecture/5_project/blog/img/02_oops.jpg", "10 Courses/02 - SoSe 2026/OOP", - "10 Courses/02 - SoSe 2026/AT/29593852 - Strings.md", - "10 Courses/02 - SoSe 2026/AT/29593952 - Regular Languages.md", - "00 Inbox/29595454 - Komplexe Zahlen und Eigenwertaufgaben.md", - "OOP - Apr", - "10 Courses/02 - SoSe 2026/Mathe II/29595454 - Mathematik II.md", + "conflict-files-obsidian-git.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593852 - Strings.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593958 - Kleene star of languages.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593952 - Regular Languages.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593940 - Formal Languages.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593935 - Kleene.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593929 - Alphabets.md", + "00 Inbox/29605546 - 29593852 - Strings.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen/29593850 - Automationtheory.md", + "10 Courses/02 - SoSe 2026/Automatentheorie und formale Sprachen", "20 Atlas/AT - Map of Content.md", "10 Courses/02 - SoSe 2026/AT/29593852 - Strings.md", "30 Library/29595284 - v01.pdf", "30 Library/29595284 - v00.pdf", "00 Inbox/29605541 - AT - Map of Content.md", - "10 Courses/02 - SoSe 2026/OOP/29605397 - OOP.md", - "10 Courses/02 - SoSe 2026/OOP/29605321 - Classes.md", - "10 Courses/02 - SoSe 2026/OOP", "10 Courses/02 - SoSe 2026/Mathe II/29595454 - Mathematik II.md", "10 Courses/02 - SoSe 2026/AT/29593975 - Regular Expressions.md", "10 Courses/02 - SoSe 2026/AT/29593958 - Kleene star of languages.md", + "10 Courses/02 - SoSe 2026/AT/29593952 - Regular Languages.md", "10 Courses/02 - SoSe 2026/AT/29593940 - Formal Languages.md", "10 Courses/02 - SoSe 2026/AT/29593935 - Kleene Star & Kleene Plus.md", "10 Courses/02 - SoSe 2026/AT/29593929 - Alphabets.md", @@ -214,7 +213,6 @@ "40 Extras/OOP_Lecture/5_project/blog/img/02_oops.jpg", "00 Inbox/29595454 - Komplexe Zahlen und Eigenwertaufgaben.md", "OOP - Apr", - "40 Extras/OOP_Lecture/3_exercises/sose26/0_teams/G01.md", "30 Library/v01.pdf", "30 Library/v00.pdf", "40 Extras/OOP_Lecture/6_exams/sose25/img/q7.svg", @@ -227,19 +225,6 @@ "40 Extras/OOP_Lecture/6_exams/sose25/img/q0.svg", "40 Extras/OOP_Lecture/6_exams/sose23/img/uml1.pdf", "40 Extras/OOP_Lecture/6_exams/sose23/img/q7.svg", - "40 Extras/OOP_Lecture/6_exams/wise24/exam_solution.pdf", - "40 Extras/OOP_Lecture/6_exams/wise24/exam.pdf", - "40 Extras/OOP_Lecture/6_exams/wise23/exam_solution.pdf", - "40 Extras/OOP_Lecture/6_exams/sose25/feedbacks.md", - "40 Extras/OOP_Lecture/6_exams/sose25/evaluation.md", - "40 Extras/OOP_Lecture/6_exams/sose24/feedbacks.md", - "40 Extras/OOP_Lecture/6_exams/sose24/evaluation.md", - "40 Extras/OOP_Lecture/6_exams/sose23/pitfalls.md", - "40 Extras/OOP_Lecture/6_exams/sose23/feedbacks.md", - "40 Extras/OOP_Lecture/6_exams/sose23/evaluation.md", - "40 Extras/OOP_Lecture/6_exams/sose22/feedbacks.md", - "40 Extras/OOP_Lecture/6_exams/sose22/evaluation.md", - "40 Extras/OOP_Lecture/6_exams/sose22/README.md", - "40 Extras/OOP_Lecture/6_exams/stories.md" + "40 Extras/OOP_Lecture/6_exams/wise24/exam_solution.pdf" ] } \ No newline at end of file diff --git a/00 Inbox/29605546 - 29593852 - Strings.md b/00 Inbox/29605546 - 29593852 - Strings.md new file mode 100644 index 0000000..2ca480a --- /dev/null +++ b/00 Inbox/29605546 - 29593852 - Strings.md @@ -0,0 +1,71 @@ +--- +created: 2026-04-08 08:52 +course: "[[29593850 - Automationtheory]]" +topic: strings +related: "[[29593929 - Alphabets]]" +type: lecture +status: 🔴 +tags: + - university +--- +## 📌 Summary + +> [!abstract] +> Overview of lecture 1 on `Wednesday, 2026/Apr/08` + +--- + +## 📝 Content + +A word (or _string_) is a finite sequence $w = a_1 a_2 ... a_n$ if characters from $Sigma$. + +> [!CONVENTION] +> We will use small letters to describe strings that are part of a language. + +> [!EXAMPLE] +> $"aa", "ab", "bba"$ and $"baab"$ are strings over $Sigma = {a, b}. + +#### Length of a string +The _length_ $abs(x)$ of a string $x = a_1 ... a_n$ is its number $abs(x) = n$ of characters. +#### Empty String +The empty string is denoted by $epsilon$, this is the neutral element. +-> $abs(epsilon) = 0$ + +## String Operations +### Concatenation +String can be concatenated, where one string is appended to another. +For strings $x = a_1 ... a_n$ and $y = b_1 ... b_m$ over alphabets $Sigma_x$ and $Sigma_y$, their _concatenation_ over the alphabet $Sigma = Sigma_x union Sigma_y$ is the string +$$x circle.small y = x y = a_1 a_2 ... a_n b_1 b_2 ... b_m$$ +> This string is of the length $abs(x y) = n + m$ + +> [!EXAMPLE] +> $x = "apple"$ +> $y = "pie"$ +> $x circle.small y = "applepie"$ + +Order of operations / Brackets do _not matter_. (Concatenation is associative but **not** commutative $x y eq.not y x$) +> $(x circle.small y) circle.small z = x circle.small (y circle.small z)$ + +Any string concatenated with the empty string $epsilon$ will result in itself. +> $x circle.small epsilon = x = epsilon circle.small x$ + +### Exponentiation + +The $n^"th"$ power $x^n$ of a string $x$ is the $(n-1)$-fold concatenation of $x$ with itself. +> $x^0 := epsilon$ +> $x^n := x^(n-1) circle.small x$ for $n in NN$ + +> [!Example] +> $x^4 = x x x x$ +> $(a b)^3 = a b a b a b$ + +### Reversing / Mirroring +For a string $x = a_1 a_2 ... a_(n-1) a_n$ of length $n$, it's _mirrored string_ is given by +$$ x^("Rev") = a_n a_(n-1)...a_2 a_1$$ +## Substrings +A string $x$ is a _substring_ of a string $y$ if $y = u x v$, where $u$ and $v$ can be arbitrary strings. +- If $u = epsilon$ then $x$ is a _prefix_ of $y$. +- If $v = epsilon$ then $x$ is a suffix of $y$. + +For strings $x$ and $y$ the quantity $abs(y)_x$ is the number of times that $x$ is a substring of $y$. + diff --git a/00 Inbox/29605547 - 29605397 - OOP.md b/00 Inbox/29605547 - 29605397 - OOP.md new file mode 100644 index 0000000..2dff315 --- /dev/null +++ b/00 Inbox/29605547 - 29605397 - OOP.md @@ -0,0 +1,18 @@ +--- +created: 2026-04-16 11:47 +course: "[[29605547 - 29605397 - OOP]]" +tags: + - university +topic: +related: +type: lecture +status: 🔴 +--- +## 📌 Summary + +> [!abstract] +> + +--- + +## 📝 Content diff --git a/00 Inbox/29605548 - 29605397 - OOP.md b/00 Inbox/29605548 - 29605397 - OOP.md new file mode 100644 index 0000000..b34839e --- /dev/null +++ b/00 Inbox/29605548 - 29605397 - OOP.md @@ -0,0 +1,18 @@ +--- +created: 2026-04-16 11:48 +course: "[[29605548 - 29605397 - OOP]]" +tags: + - university +topic: +related: +type: lecture +status: 🔴 +--- +## 📌 Summary + +> [!abstract] +> + +--- + +## 📝 Content diff --git a/10 Courses/02 - SoSe 2026/OOP/29605321 - Classes.md b/10 Courses/02 - SoSe 2026/OOP/29605321 - Classes.md index ec53dfb..8fe8b13 100644 --- a/10 Courses/02 - SoSe 2026/OOP/29605321 - Classes.md +++ b/10 Courses/02 - SoSe 2026/OOP/29605321 - Classes.md @@ -1,6 +1,6 @@ --- created: 2026-04-16 08:01 -course: "[[29605397 - OOP]]" +course: "[[29605548 - 29605397 - OOP]]" topic: classes related: type: lecture diff --git a/10 Courses/02 - SoSe 2026/OOP/29605397 - OOP.md b/10 Courses/02 - SoSe 2026/OOP/29605397 - OOP.md deleted file mode 100644 index cc31725..0000000 --- a/10 Courses/02 - SoSe 2026/OOP/29605397 - OOP.md +++ /dev/null @@ -1,6 +0,0 @@ ---- -created: 2026-04-16 09:17 -course: "[[29605397 - OOP]]" -tags: - - university ---- diff --git a/40 Extras/OOP_Lecture b/40 Extras/OOP_Lecture new file mode 160000 index 0000000..55aef6d --- /dev/null +++ b/40 Extras/OOP_Lecture @@ -0,0 +1 @@ +Subproject commit 55aef6d92eaf8e2d7f20229b55f56c10db7b928d