ramirezalex / hackerrank

Efficient HackerRank solutions in JavaScript (⬡.js)

Efficient HackerRank solutions in JavaScript programmed by Gabriel Giordano

10 Days of Statistics

	Day	Problem	Solution	Difficulty	Points	Note
⭐	9	Multiple Linear Regression (Last day)	JavaScript	Medium	30	Implementation of a research from Ahmad Farooq and Khan Hamid, from C to JavaScript with some custom modifications
	8	Least Square Regression Line	JavaScript	Easy	30
	7	Spearman's Rank Correlation Coefficient	JavaScript	Easy	30
	7	Pearson Correlation Coefficient I	JavaScript	Easy	30
	6	The Central Limit Theorem III	JavaScript	Easy	30
	6	The Central Limit Theorem II	JavaScript	Easy	30
	6	The Central Limit Theorem I	JavaScript	Easy	30
	5	Normal Distribution II	JavaScript	Easy	30
	5	Normal Distribution I	JavaScript	Easy	30
	5	Poison Distribution II	JavaScript	Easy	30
	5	Poison Distribution I	JavaScript	Easy	30
	4	Geometric Distribution II	JavaScript	Easy	30
	4	Geometric Distribution I	JavaScript	Easy	30
	4	Binomial Distribution II	JavaScript	Easy	30
	4	Binomial Distribution I	JavaScript	Easy	30
	2	Compound Event Probability	JavaScript
	2	More Dice	JavaScript
	2	Basic Probability	JavaScript
	1	Standard Deviation	JavaScript	Easy	30
	1	Interquartile Range	JavaScript	Easy	30
	1	Quartiles	JavaScript	Easy	30
	0	Weighted Mean	JavaScript	Easy	30
	0	Mean, Median, and Mode	JavaScript	Easy	30

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Algorithms

Implementation

	Problem	Solution	Difficulty	Points	Note
⭐	Matrix Layer Rotation	JavaScript	Hard	80	Math solution to the problem, O(1) if the loop to print the result isn't considered, otherwise O(m*n)
⭐	ACM ICPC Team	JavaScript	Easy	25	Using bitwise operations, and a custom Hamming Weight implementation to count ones, because the HackerRank's v8 version hasn't yet a BigInt implementation. Best case O(n^2) where n is the topics length
⭐	Queen's Attack II	JavaScript	Medium	30	Math solution to the problem, O(k), where k is the number of obstacles
⭐	Modified Kaprekar Numbers	JavaScript	Easy	30	Math and very performatic solution, without using Strings nor brute force, O(n), where n = q - p
	Equalize the Array	JavaScript	Easy	20	O(n)
⭐	Jumping on the Clouds	JavaScript	Easy	20	O(log n)
⭐	Repeated String	JavaScript	Easy	20	The algorithm doesn't count the string a second time, both best and worst case is O(n) where n is the length of the string
	Lisa's Workbook	JavaScript	Easy	25
	Bigger is Greater	JavaScript	Medium	35
	Organizing Containers of Balls	JavaScript	Medium	30
	The Time in Words	JavaScript	Medium	25	O(1)
	Beautiful Triplets	JavaScript	Easy	20	O(n)
	Minimum Distances	JavaScript	Easy	20	O(n)
	Halloween Sale	JavaScript	Easy	20	O(1)
	Non-Divisible Subset	JavaScript	Medium	20
	Cut the Sticks	JavaScript	Easy	25
	Library Fine	JavaScript	Easy	15	O(1)
	Sherlock and Squares	JavaScript	Easy	20	O(1)
	Append and Delete	JavaScript	Easy	20	O(min(s, t))
	Extra Long Factorials	JavaScript	Medium	20
	Service Lane	JavaScript	Easy	20
	Chocolate Feast	JavaScript	Easy	25	O(1)
	Find Digits	JavaScript	Easy	25	O(n)
	Jumping on the Clouds: Revisited	JavaScript	Easy	15	O(n / k) where k is the number of jumps
	Sequence Equation	JavaScript	Easy	20
	Circular Array Rotation	JavaScript	Easy	20
	Save the Prisoner!	JavaScript	Easy	15	O(1)
⭐	Viral Advertising	JavaScript	Easy	15	Alternative way to solve it using this integer sequence formula: https://oeis.org/A061418
	Beautiful Days at the Movies	JavaScript	Easy	15	O(n)
	Angry Professor	JavaScript	Easy	20	O(n)
	Utopian Tree	JavaScript	Easy	20	O(1)
	Designer PDF Viewer	JavaScript	Easy	20
	The Hurdle Race	JavaScript	Easy	15	O(1)
	Climbing the Leaderboard	JavaScript	Medium	20	O(n + log(m))
	Picking Numbers	JavaScript	Easy	20	O(1)
⭐	Forming a Magic Square	JavaScript	Medium	20	Using Édouard Lucas general formula to generate all possible magic squares of order 3
	Cats and a Mouse	JavaScript	Easy	15	O(1)
	Eletronics Shop	JavaScript	Easy	15
	Counting Valleys	JavaScript	Easy	15	O(n)
	Drawing Book	JavaScript	Easy	10	O(1)
	Sock Merchant	JavaScript	Easy	10	O(1)
	Bon Appétit	JavaScript	Easy	10	O(n)
	Day of the Programmer	JavaScript	Easy	10	O(1)
	Migratory Birds	JavaScript	Easy	10
	Divisible Sum Pairs	JavaScript	Easy	10
	Birthday Chocolate	JavaScript	Easy	10
	Breaking the Records	JavaScript	Easy	10	O(n)
	Between Two Sets	JavaScript	Easy	10	Using Euclid's division algorithm for greatest common divisor
	Kangaroo	JavaScript	Easy	10
	Apple and Orange	JavaScript	Easy	10
	Grading Students	JavaScript	Easy	10

Data Structures

	Problem	Solution	Difficulty	Points	Note
	Array Manipulation	JavaScript	Hard	60
	Sparse Arrays	JavaScript	Medium	25
	Dynamic Array	JavaScript	Easy	15
	Array DS	JavaScript	Easy	10

Constructive Algorithms

	Problem	Solution	Difficulty	Points	Note
	New Year Chaos	JavaScript	Medium	40

Warmup

	Problem	Solution	Difficulty	Points	Note
	Time Conversion	JavaScript	Easy	15
	Birthday Cake Candles	JavaScript	Easy	10
	Mini-Max Sum	JavaScript	Easy	10
	Staircase	JavaScript	Easy	10
	Plus Minus	JavaScript	Easy	10
	Diagonal Difference	JavaScript	Easy	10
	A Very Big Sum	JavaScript	Easy	10
	Compare the Triplets	JavaScript	Easy	10

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Mathematics

	Problem	Solution	Difficulty	Points	Note
	Army Game	JavaScript	Easy	10
	Minimum Height Triangle	JavaScript	Easy	10
	Handshake	JavaScript	Easy	10
	Maximum Draws	JavaScript	Easy	5
	Find the Point	JavaScript	Easy	5

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Interview Preparation Kit

Arrays

	Problem	Solution	Difficulty	Points	Note
	Minimun Swaps 2	JavaScript	Medium	40
	Arrays: Left Rotation	JavaScript	Easy	15
	2D Array - DS	JavaScript	Easy	15