diff --git a/translations/README-el.md b/translations/README-el.md index 71bedc6..8a83dbd 100644 --- a/translations/README-el.md +++ b/translations/README-el.md @@ -461,3 +461,192 @@ Εάν μερικές διαλέξεις είναι πολύ μαθηματικές, μπορείς να μεταβείς προς τα κάτω και να παρακολουθήσεις μερικά βίντεο σχετικά με τα διακριτά μαθηματικά για να πάρεις όλες τις γνώσεις που απαιτούνται. +## Δομές Δεδομένων + +- ### Πίνακες + - Υλοποίησε μία λίστα, η οποία αλλάζει αυτόματα μέγεθος. + - [ ] Περιγραφή: + - [Πίνακες(EN) (video)](https://www.coursera.org/learn/data-structures/lecture/OsBSF/arrays) + - [UCBerkley CS61B - Linear and Multi-Dim Arrays (video)](https://youtu.be/Wp8oiO_CZZE?t=15m32s) + - [Basic Arrays (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Basic-arrays/149042/177104-4.html) + - [Multi-dim (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Multidimensional-arrays/149042/177105-4.html) + - [Dynamic Arrays (video)](https://www.coursera.org/learn/data-structures/lecture/EwbnV/dynamic-arrays) + - [Jagged Arrays (video)](https://www.youtube.com/watch?v=1jtrQqYpt7g) + - [Jagged Arrays (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Jagged-arrays/149042/177106-4.html) + - [Resizing arrays (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Resizable-arrays/149042/177108-4.html) + - [ ] Υλοποίησε μία συλλογή (ευμετάβλητο πίνακα με αυτόματη αλλαγή μεγέθους): + - [ ] Κάνε πρακτική σε κώδικα χρησιμοποιώντας πίνακες και δείκτες, και pointer math για να πας σε ένα δείκτη από το να χρησιμοποιήσεις ευρετηρίαση. + - [ ] new raw data array with allocated memory + - can allocate int array under the hood, just not use its features + - start with 16, or if starting number is greater, use power of 2 - 16, 32, 64, 128 + - [ ] size() - αριθμός των στοιχείων + - [ ] capacity() - αριθμός στοιχείων που μπορεί να περιέχει + - [ ] is_empty() + - [ ] at(index) - επιστρέφει που υπάρχει στη θέση index, *εκρύγνειται* αν ο δείκτης είναι εκτός συνόρων του πίνακα + - [ ] push(item) + - [ ] insert(index, item) - εισάγει ένα σημείο στη θέση index, μετακινεί την τιμή του index και σύρει όλα τα στοιχεία στα δεξιά + - [ ] prepend(item) - εισάγει το αντικείμενο στην αρχή της συλλογής(insert(0,item)) + - [ ] pop() - αφαιρεί από το τέλος, επιστρέφει την τιμή + - [ ] delete(index) - διγράφη το στοιχείο στη θέση index, σύρει όλα τα στοιχεία στα αριστερά + - [ ] remove(item) - ψάχνει για την τιμή και διαγράφει το δείκτη που την έχει (ακόμα και αν είναι σε περισσότερες από 1 θέσεις) + - [ ] find(item) - ψάχνει για την τιμή και επιστρέφει τον πρώτο δείκτη με αυτή την τιμή, -1 έαν δε βρεθεί + - [ ] resize(new_capacity) // private function + - όταν φτάνεις στη χωρητικώτητα, άλλαξε το μέγεθος του πίνακα κατά το διπλάσιο + - όταν αφαιρείς ένα στοιχείο, εάν το μέγεθος είναι 1/4 της χωρητικότητας, άλλαξε το μέγεθος κατά το μισό + - [ ] Χρόνος + - O(1) για πρόσθεση/αφαίρεση στο τέλος (απελευθέρωση των δεσμευμένων θέσεων για περισσότερο χώρο) + - O(n) για πρόσθεση/αφαίρεση αλλού + - [ ] Χώρος + - συνεχόμενος στη μνήμη, έτσι η μικρή απόσταση βοηθάει στην απόδοση + - απαιτούμενος χώρος = (χωρητικότητα πίνακα, η οποία είναι >= n) * μέγεθος του στοιχείου, αλλά ακόμα και αν είναι 2n => O(n) + +- ### Συνδεδεμένες λίστες + - [ ] Περιγραφή: + - [ ] [Singly Linked Lists (video)](https://www.coursera.org/learn/data-structures/lecture/kHhgK/singly-linked-lists) + - [ ] [CS 61B - Linked Lists (video)](https://www.youtube.com/watch?v=sJtJOtXCW_M&list=PL-XXv-cvA_iAlnI-BQr9hjqADPBtujFJd&index=5) + - [ ] [C Code (video)](https://www.youtube.com/watch?v=QN6FPiD0Gzo) + - not the whole video, just portions about Node struct and memory allocation. + - [ ] Linked List vs Arrays: + - [Core Linked Lists Vs Arrays (video)](https://www.coursera.org/learn/data-structures-optimizing-performance/lecture/rjBs9/core-linked-lists-vs-arrays) + - [In The Real World Linked Lists Vs Arrays (video)](https://www.coursera.org/learn/data-structures-optimizing-performance/lecture/QUaUd/in-the-real-world-lists-vs-arrays) + - [ ] [why you should avoid linked lists (video)](https://www.youtube.com/watch?v=YQs6IC-vgmo) + - [ ] Gotcha: you need pointer to pointer knowledge: + (for when you pass a pointer to a function that may change the address where that pointer points) + This page is just to get a grasp on ptr to ptr. I don't recommend this list traversal style. Readability and maintainability suffer due to cleverness. + - [Pointers to Pointers](https://www.eskimo.com/~scs/cclass/int/sx8.html) + - [ ] υλοποίηση (Το έκανα με δείκτη ουράς και χωρίς): + + # untill here + + - [ ] size() - returns number of data elements in list + - [ ] empty() - bool returns true if empty + - [ ] value_at(index) - returns the value of the nth item (starting at 0 for first) + - [ ] push_front(value) - adds an item to the front of the list + - [ ] pop_front() - remove front item and return its value + - [ ] push_back(value) - adds an item at the end + - [ ] pop_back() - removes end item and returns its value + - [ ] front() - get value of front item + - [ ] back() - get value of end item + - [ ] insert(index, value) - insert value at index, so current item at that index is pointed to by new item at index + - [ ] erase(index) - removes node at given index + - [ ] value_n_from_end(n) - returns the value of the node at nth position from the end of the list + - [ ] reverse() - reverses the list + - [ ] remove_value(value) - removes the first item in the list with this value + - [ ] Doubly-linked List + - [Description (video)](https://www.coursera.org/learn/data-structures/lecture/jpGKD/doubly-linked-lists) + - No need to implement + +- ### Stack + - [ ] [Stacks (video)](https://www.coursera.org/learn/data-structures/lecture/UdKzQ/stacks) + - [ ] [Using Stacks Last-In First-Out (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Using-stacks-last-first-out/149042/177120-4.html) + - [ ] Will not implement. Implementing with array is trivial. + +- ### Queue + - [ ] [Using Queues First-In First-Out(video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Using-queues-first-first-out/149042/177122-4.html) + - [ ] [Queue (video)](https://www.coursera.org/learn/data-structures/lecture/EShpq/queue) + - [ ] [Circular buffer/FIFO](https://en.wikipedia.org/wiki/Circular_buffer) + - [ ] [Priority Queues (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Priority-queues-deques/149042/177123-4.html) + - [ ] Implement using linked-list, with tail pointer: + - enqueue(value) - adds value at position at tail + - dequeue() - returns value and removes least recently added element (front) + - empty() + - [ ] Implement using fixed-sized array: + - enqueue(value) - adds item at end of available storage + - dequeue() - returns value and removes least recently added element + - empty() + - full() + - [ ] Cost: + - a bad implementation using linked list where you enqueue at head and dequeue at tail would be O(n) + because you'd need the next to last element, causing a full traversal each dequeue + - enqueue: O(1) (amortized, linked list and array [probing]) + - dequeue: O(1) (linked list and array) + - empty: O(1) (linked list and array) + +- ### Hash table + - [ ] Videos: + - [ ] [Hashing with Chaining (video)](https://www.youtube.com/watch?v=0M_kIqhwbFo&list=PLUl4u3cNGP61Oq3tWYp6V_F-5jb5L2iHb&index=8) + - [ ] [Table Doubling, Karp-Rabin (video)](https://www.youtube.com/watch?v=BRO7mVIFt08&index=9&list=PLUl4u3cNGP61Oq3tWYp6V_F-5jb5L2iHb) + - [ ] [Open Addressing, Cryptographic Hashing (video)](https://www.youtube.com/watch?v=rvdJDijO2Ro&index=10&list=PLUl4u3cNGP61Oq3tWYp6V_F-5jb5L2iHb) + - [ ] [PyCon 2010: The Mighty Dictionary (video)](https://www.youtube.com/watch?v=C4Kc8xzcA68) + - [ ] [(Advanced) Randomization: Universal & Perfect Hashing (video)](https://www.youtube.com/watch?v=z0lJ2k0sl1g&list=PLUl4u3cNGP6317WaSNfmCvGym2ucw3oGp&index=11) + - [ ] [(Advanced) Perfect hashing (video)](https://www.youtube.com/watch?v=N0COwN14gt0&list=PL2B4EEwhKD-NbwZ4ezj7gyc_3yNrojKM9&index=4) + + - [ ] Online Courses: + - [ ] [Understanding Hash Functions (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Understanding-hash-functions/149042/177126-4.html) + - [ ] [Using Hash Tables (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Using-hash-tables/149042/177127-4.html) + - [ ] [Supporting Hashing (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Supporting-hashing/149042/177128-4.html) + - [ ] [Language Support Hash Tables (video)](https://www.lynda.com/Developer-Programming-Foundations-tutorials/Language-support-hash-tables/149042/177129-4.html) + - [ ] [Core Hash Tables (video)](https://www.coursera.org/learn/data-structures-optimizing-performance/lecture/m7UuP/core-hash-tables) + - [ ] [Data Structures (video)](https://www.coursera.org/learn/data-structures/home/week/3) + - [ ] [Phone Book Problem (video)](https://www.coursera.org/learn/data-structures/lecture/NYZZP/phone-book-problem) + - [ ] distributed hash tables: + - [Instant Uploads And Storage Optimization In Dropbox (video)](https://www.coursera.org/learn/data-structures/lecture/DvaIb/instant-uploads-and-storage-optimization-in-dropbox) + - [Distributed Hash Tables (video)](https://www.coursera.org/learn/data-structures/lecture/tvH8H/distributed-hash-tables) + + - [ ] implement with array using linear probing + - hash(k, m) - m is size of hash table + - add(key, value) - if key already exists, update value + - exists(key) + - get(key) + - remove(key) + +## More Knowledge + +- ### Binary search + - [ ] [Binary Search (video)](https://www.youtube.com/watch?v=D5SrAga1pno) + - [ ] [Binary Search (video)](https://www.khanacademy.org/computing/computer-science/algorithms/binary-search/a/binary-search) + - [ ] [detail](https://www.topcoder.com/community/data-science/data-science-tutorials/binary-search/) + - [ ] Implement: + - binary search (on sorted array of integers) + - binary search using recursion + +- ### Bitwise operations + - [ ] [Bits cheat sheet](https://github.com/jwasham/coding-interview-university/blob/master/extras/cheat%20sheets/bits-cheat-cheet.pdf) - you should know many of the powers of 2 from (2^1 to 2^16 and 2^32) + - [ ] Get a really good understanding of manipulating bits with: &, |, ^, ~, >>, << + - [ ] [words](https://en.wikipedia.org/wiki/Word_(computer_architecture)) + - [ ] Good intro: + [Bit Manipulation (video)](https://www.youtube.com/watch?v=7jkIUgLC29I) + - [ ] [C Programming Tutorial 2-10: Bitwise Operators (video)](https://www.youtube.com/watch?v=d0AwjSpNXR0) + - [ ] [Bit Manipulation](https://en.wikipedia.org/wiki/Bit_manipulation) + - [ ] [Bitwise Operation](https://en.wikipedia.org/wiki/Bitwise_operation) + - [ ] [Bithacks](https://graphics.stanford.edu/~seander/bithacks.html) + - [ ] [The Bit Twiddler](http://bits.stephan-brumme.com/) + - [ ] [The Bit Twiddler Interactive](http://bits.stephan-brumme.com/interactive.html) + - [ ] 2s and 1s complement + - [Binary: Plusses & Minuses (Why We Use Two's Complement) (video)](https://www.youtube.com/watch?v=lKTsv6iVxV4) + - [1s Complement](https://en.wikipedia.org/wiki/Ones%27_complement) + - [2s Complement](https://en.wikipedia.org/wiki/Two%27s_complement) + - [ ] count set bits + - [4 ways to count bits in a byte (video)](https://youtu.be/Hzuzo9NJrlc) + - [Count Bits](https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetKernighan) + - [How To Count The Number Of Set Bits In a 32 Bit Integer](http://stackoverflow.com/questions/109023/how-to-count-the-number-of-set-bits-in-a-32-bit-integer) + - [ ] round to next power of 2: + - [Round Up To Next Power Of Two](http://bits.stephan-brumme.com/roundUpToNextPowerOfTwo.html) + - [ ] swap values: + - [Swap](http://bits.stephan-brumme.com/swap.html) + - [ ] absolute value: + - [Absolute Integer](http://bits.stephan-brumme.com/absInteger.html) + +## Trees + +- ### Trees - Notes & Background + - [ ] [Series: Core Trees (video)](https://www.coursera.org/learn/data-structures-optimizing-performance/lecture/ovovP/core-trees) + - [ ] [Series: Trees (video)](https://www.coursera.org/learn/data-structures/lecture/95qda/trees) + - basic tree construction + - traversal + - manipulation algorithms + - BFS (breadth-first search) + - [MIT (video)](https://www.youtube.com/watch?v=s-CYnVz-uh4&list=PLUl4u3cNGP61Oq3tWYp6V_F-5jb5L2iHb&index=13) + - level order (BFS, using queue) + time complexity: O(n) + space complexity: best: O(1), worst: O(n/2)=O(n) + - DFS (depth-first search) + - [MIT (video)](https://www.youtube.com/watch?v=AfSk24UTFS8&list=PLUl4u3cNGP61Oq3tWYp6V_F-5jb5L2iHb&index=14) + - notes: + time complexity: O(n) + space complexity: + best: O(log n) - avg. height of tree + worst: O(n) + - inorder (DFS: left, self, right) + - postorder (DFS: left, right, self) + - preorder (DFS: self, left, right) \ No newline at end of file