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JavaScript Algoritmi i Strukture podataka
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Ovaj repozitorij sadrzi JavaScript bazirane primjere od vise popularnih Algoritama i Struktura podataka.
Svaki Algoritam i Struktura podataka ima svoj vlastiti, poseban README koji je povezan sa objasnjenjima i linkovima za dalje citanje (ukljucujuci i Youtube video materijale).
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Strukture Podataka
Struktura podataka je poseban način organiziranja i pohranjivanja podataka u računar kako bi istim mogloe ofikasno pristupiti i mijenjati. Preciznije, struktura podataka je zbirka podataka vrijednosti, odnosa među njima, funkcije ili operacije koje se mogu primijeniti na podatke.
B
- Pocetnik - Beginner, A
- Napredni - Advanced
B
Linked ListB
Doubly Linked ListB
QueueB
StackB
Hash TableB
Heap - max and min heap versionsB
Priority QueueA
TrieA
TreeA
Binary Search TreeA
AVL TreeA
Red-Black TreeA
Segment Tree - with min/max/sum range queries examplesA
Fenwick Tree (Binary Indexed Tree)
A
Graph (both directed and undirected)A
Disjoint SetA
Bloom Filter
Algoritmi
Algoritam je nedvosmislena specifikacija kako riješiti klasu problema. To je skup pravila koja precizno definiraju niz operacija.
B
- Pocetnik - Beginner, A
- Napredni - Advanced
Algoritmi po temama
- Matematika
B
Bit Manipulation - postaviti / dobiti / ažurirati / očistiti bitove, množenje / dijeljenje sa dva, napraviti negativne itdB
FactorialB
Fibonacci Number - klasične verzije i verzije zatvorenog oblikaB
Prime Factors - pronalaženje glavnih faktora i njihovo brojanje pomoću Hardy-Ramanujanove teoremeB
Primality Test (trial division method)B
Euclidean Algorithm - calculate the Greatest Common Divisor (GCD)B
Least Common Multiple (LCM)B
Sieve of Eratosthenes - finding all prime numbers up to any given limitB
Is Power of Two - check if the number is power of two (naive and bitwise algorithms)B
Pascal's TriangleB
Complex Number - complex numbers and basic operations with themB
Radian & Degree - radians to degree and backwards conversionB
Fast PoweringB
Horner's method - polynomial evaluationB
Matrices - matrices and basic matrix operations (multiplication, transposition, etc.)B
Euclidean Distance - distance between two points/vectors/matricesA
Integer PartitionA
Square Root - Newton's methodA
Liu Hui π Algorithm - approximate π calculations based on N-gonsA
Discrete Fourier Transform - decompose a function of time (a signal) into the frequencies that make it up
- Setovi
B
Cartesian Product - product of multiple setsB
Fisher–Yates Shuffle - random permutation of a finite sequenceA
Power Set - all subsets of a set (bitwise and backtracking solutions)A
Permutations (with and without repetitions)A
Combinations (with and without repetitions)A
Longest Common Subsequence (LCS)A
Longest Increasing SubsequenceA
Shortest Common Supersequence (SCS)A
Knapsack Problem - "0/1" and "Unbound" onesA
Maximum Subarray - "Brute Force" and "Dynamic Programming" (Kadane's) versionsA
Combination Sum - find all combinations that form specific sum
- Stringovi
B
Hamming Distance - number of positions at which the symbols are differentA
Levenshtein Distance - minimum edit distance between two sequencesA
Knuth–Morris–Pratt Algorithm (KMP Algorithm) - substring search (pattern matching)A
Z Algorithm - substring search (pattern matching)A
Rabin Karp Algorithm - substring searchA
Longest Common SubstringA
Regular Expression Matching
- Pretrage
B
Linear SearchB
Jump Search (or Block Search) - search in sorted arrayB
Binary Search - search in sorted arrayB
Interpolation Search - search in uniformly distributed sorted array
- Sortiranje
B
Bubble SortB
Selection SortB
Insertion SortB
Heap SortB
Merge SortB
Quicksort - in-place and non-in-place implementationsB
ShellsortB
Counting SortB
Radix Sort
- Linkovane Liste
- Trees
B
Depth-First Search (DFS)B
Breadth-First Search (BFS)
- Grafovi
B
Depth-First Search (DFS)B
Breadth-First Search (BFS)B
Kruskal’s Algorithm - finding Minimum Spanning Tree (MST) for weighted undirected graphA
Dijkstra Algorithm - finding the shortest paths to all graph vertices from single vertexA
Bellman-Ford Algorithm - finding the shortest paths to all graph vertices from single vertexA
Floyd-Warshall Algorithm - find the shortest paths between all pairs of verticesA
Detect Cycle - for both directed and undirected graphs (DFS and Disjoint Set based versions)A
Prim’s Algorithm - finding Minimum Spanning Tree (MST) for weighted undirected graphA
Topological Sorting - DFS methodA
Articulation Points - Tarjan's algorithm (DFS based)A
Bridges - DFS based algorithmA
Eulerian Path and Eulerian Circuit - Fleury's algorithm - Visit every edge exactly onceA
Hamiltonian Cycle - Visit every vertex exactly onceA
Strongly Connected Components - Kosaraju's algorithmA
Travelling Salesman Problem - shortest possible route that visits each city and returns to the origin city
- Kriptografija
B
Polynomial Hash - rolling hash function based on polynomialB
Rail Fence Cipher - a transposition cipher algorithm for encoding messagesB
Caesar Cipher - simple substitution cipherB
Hill Cipher - substitution cipher based on linear algebra
- Masinsko ucenje
B
NanoNeuron - 7 simple JS functions that illustrate how machines can actually learn (forward/backward propagation)B
k-NN - k-nearest neighbors classification algorithmB
k-Means - k-Means clustering algorithm
- Procesiranje slika
B
Seam Carving - content-aware image resizing algorithm
- Nekategorizirani
B
Tower of HanoiB
Square Matrix Rotation - in-place algorithmB
Jump Game - backtracking, dynamic programming (top-down + bottom-up) and greedy examplesB
Unique Paths - backtracking, dynamic programming and Pascal's Triangle based examplesB
Rain Terraces - trapping rain water problem (dynamic programming and brute force versions)B
Recursive Staircase - count the number of ways to reach to the top (4 solutions)B
Best Time To Buy Sell Stocks - divide and conquer and one-pass examplesA
N-Queens ProblemA
Knight's Tour
Algoritmi Paradigme
Algoritmička paradigma je generička metoda ili pristup koji leži u osnovi dizajna klase algoritama. To je apstrakcija viša od pojma algoritma, baš kao i sto je i algoritam viša apstrakcija od računarskog programa.
- ** Brute Force ** - sagledajte sve mogućnosti i odaberite najbolje rješenje
B
Linear SearchB
Rain Terraces - trapping rain water problemB
Recursive Staircase - count the number of ways to reach to the topA
Maximum SubarrayA
Travelling Salesman Problem - shortest possible route that visits each city and returns to the origin cityA
Discrete Fourier Transform - decompose a function of time (a signal) into the frequencies that make it up
- Greedy - odaberite najbolju opciju u ovom trenutku, bez ikakvog razmatranja za budućnost
B
Jump GameA
Unbound Knapsack ProblemA
Dijkstra Algorithm - finding the shortest path to all graph verticesA
Prim’s Algorithm - finding Minimum Spanning Tree (MST) for weighted undirected graphA
Kruskal’s Algorithm - finding Minimum Spanning Tree (MST) for weighted undirected graph
- Divide and Conquer - podijeli problem na manje dijelove, a zatim riješi te dijelove
B
Binary SearchB
Tower of HanoiB
Pascal's TriangleB
Euclidean Algorithm - calculate the Greatest Common Divisor (GCD)B
Merge SortB
QuicksortB
Tree Depth-First Search (DFS)B
Graph Depth-First Search (DFS)B
Matrices - generating and traversing the matrices of different shapesB
Jump GameB
Fast PoweringB
Best Time To Buy Sell Stocks - divide and conquer and one-pass examplesA
Permutations (with and without repetitions)A
Combinations (with and without repetitions)
- Dynamic Programming - izgraditi rješenje koristeći prethodno pronađena podrešenja
B
Fibonacci NumberB
Jump GameB
Unique PathsB
Rain Terraces - trapping rain water problemB
Recursive Staircase - count the number of ways to reach to the topB
Seam Carving - content-aware image resizing algorithmA
Levenshtein Distance - minimum edit distance between two sequencesA
Longest Common Subsequence (LCS)A
Longest Common SubstringA
Longest Increasing SubsequenceA
Shortest Common SupersequenceA
0/1 Knapsack ProblemA
Integer PartitionA
Maximum SubarrayA
Bellman-Ford Algorithm - finding the shortest path to all graph verticesA
Floyd-Warshall Algorithm - find the shortest paths between all pairs of verticesA
Regular Expression Matching
- Backtracking - slično kao brute force, pokušaj generirati sva moguća rješenja, ali svaki put kada generiramo sljedeće rješenje testiramo
da li zadovoljava sve uvjete, a tek onda nastavimo s generiranjem sljedećih rješenja. U suprotnom, vrati se i idi dalje trazeci drugi put pronalaženja rješenja. Uobičajeno se koristi DFS traversal of state-space.
B
Jump GameB
Unique PathsB
Power Set - all subsets of a setA
Hamiltonian Cycle - Visit every vertex exactly onceA
N-Queens ProblemA
Knight's TourA
Combination Sum - find all combinations that form specific sum
- Branch & Bound - pamti se najjefikasnije rješenje pronađeno u svakoj fazi povratka unatrag, pretraži i upotrijebi cijenu tog rješenja pronađenog do sada kao donju granicu cijene za najjeftinije/najefikasnije (koje trosi najmanje resursa) rješenje problema, kako bi se odbacila djelomična rješenja s troškovima većim od do sada pronađenog najjeftinijeg/najefikasnijeg rješenja. Uobicajeno se koristi BFS traversal u kombinaciji sa DFS traversal of state-space tree.
Kako koristiti ovaj repozitorij
Instaliraj dependencies
npm install
Pokreni ESLint
You may want to run it to check code quality.
npm run lint
Pokreni sve tests
npm test
Pokreni testove po imenu
npm test -- 'LinkedList'
Problematika i kako je rijesiti
In case if linting or testing is failing try to delete the node_modules
folder and re-install npm packages:
rm -rf ./node_modules
npm i
Playground
You may play with data-structures and algorithms in ./src/playground/playground.js
file and write
tests for it in ./src/playground/__test__/playground.test.js
.
Then just simply run the following command to test if your playground code works as expected:
npm test -- 'playground'
Useful Information
References
▶ Data Structures and Algorithms on YouTube
Big O Notation
Big O notation is used to classify algorithms according to how their running time or space requirements grow as the input size grows. On the chart below you may find most common orders of growth of algorithms specified in Big O notation.
Source: Big O Cheat Sheet.
Below is the list of some of the most used Big O notations and their performance comparisons against different sizes of the input data.
Big O Notation | Computations for 10 elements | Computations for 100 elements | Computations for 1000 elements |
---|---|---|---|
O(1) | 1 | 1 | 1 |
O(log N) | 3 | 6 | 9 |
O(N) | 10 | 100 | 1000 |
O(N log N) | 30 | 600 | 9000 |
O(N^2) | 100 | 10000 | 1000000 |
O(2^N) | 1024 | 1.26e+29 | 1.07e+301 |
O(N!) | 3628800 | 9.3e+157 | 4.02e+2567 |
Data Structure Operations Complexity
Data Structure | Access | Search | Insertion | Deletion | Comments |
---|---|---|---|---|---|
Array | 1 | n | n | n | |
Stack | n | n | 1 | 1 | |
Queue | n | n | 1 | 1 | |
Linked List | n | n | 1 | n | |
Hash Table | - | n | n | n | In case of perfect hash function costs would be O(1) |
Binary Search Tree | n | n | n | n | In case of balanced tree costs would be O(log(n)) |
B-Tree | log(n) | log(n) | log(n) | log(n) | |
Red-Black Tree | log(n) | log(n) | log(n) | log(n) | |
AVL Tree | log(n) | log(n) | log(n) | log(n) | |
Bloom Filter | - | 1 | 1 | - | False positives are possible while searching |
Array Sorting Algorithms Complexity
Name | Best | Average | Worst | Memory | Stable | Comments |
---|---|---|---|---|---|---|
Bubble sort | n | n2 | n2 | 1 | Yes | |
Insertion sort | n | n2 | n2 | 1 | Yes | |
Selection sort | n2 | n2 | n2 | 1 | No | |
Heap sort | n log(n) | n log(n) | n log(n) | 1 | No | |
Merge sort | n log(n) | n log(n) | n log(n) | n | Yes | |
Quick sort | n log(n) | n log(n) | n2 | log(n) | No | Quicksort is usually done in-place with O(log(n)) stack space |
Shell sort | n log(n) | depends on gap sequence | n (log(n))2 | 1 | No | |
Counting sort | n + r | n + r | n + r | n + r | Yes | r - biggest number in array |
Radix sort | n * k | n * k | n * k | n + k | Yes | k - length of longest key |