To join the Challenge read Lets Join the #100DaysOfAlgorithm and get started.
##Logs
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duplicate_encoder: It converts a string to a new string where each character in the new string is '(' if that character appears only once in the original string, or ')' if that character appears more than once in the original string.
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digital_root: A digital root is the recursive sum of all the digits in a number. Given n, it takes the sum of the digits of n. If that value has two digits, it continues reducing in this way until a single-digit number is produced. This is only applicable to the natural numbers.
- pairity_outliner: You are given an array (which will have a length of at least 3, but could be very large) containing integers. The array is either entirely comprised of odd integers or entirely comprised of even integers except for a single integer N. It contains a method that takes the array as an argument and returns N.
- exes_and_ohs: Checks to see if a string has the same amount of 'x's and 'o's. The method will return a boolean and is case insensitive. The string can contain any char.
- trailling_zero: Finds to total number of trailling zeros in the factorial of a supplied number.
- next_big_number: A function that takes a positive integer number and returns the next bigger number formed by the same digits. If no bigger number can be composed using those digits, it return -1. Phew, it was tough.
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perfect_power: Checks if the number is perfect power and returns the corresponding pair i^j. It returns nil if the number is not a perfect power.
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to_camel_case: It converts dash/underscore delimited words into camel casing. For example : to_camel_case("the-stealth-warrior") retutns "theStealthWarrior"
- bits_battle: A list of positive integers is given. The odd numbers from the list will fight using their 1 bits from their binary representation, while the even numbers will fight using their 0 bits. This way the function returns the winner or a tie.
- bits_war: In addition to the 9th challenge, the war has expanded and become dirtier and meaner; both even and odd numbers will fight with their pointy 1s. And negative integers are coming into play as well.
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descending_order: It takes any non-negative integer as a argument and returns it with it's digits in descending order.
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largest_5_digit: It returns the largest five digit sequence of number found within the number given. The number will be passed in as a string of only digits. It should return a five digit integer.
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palindrome_chain_length: It takes a positive number and returns the number of special steps needed to obtain a palindrome. The special step is: "reverse the digits, and add to the original number".
- hashtag_generator: It takes a string and does the following:
-If the final result is longer than 140 chars it returns false.
-If the input is a empty string it returns false.
-It starts with a hashtag (#).
-All words have their first letter capitalized.
for example input of " hello world " => "#HelloWorld"
- first_non_repeating_letter: It takes a string input, and returns the first character that is not repeated anywhere in the string. In addition, upper and lowercase letters are considered the same character, but the function returns the correct case for the initial letter. If a string contains all repeating characters, it returns the empty string ("").
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count_smiley: Given an array (arr) as an argument the function countSmileys returns the total number of smiling faces. The rules for smiling faces are :
-Each smiley face must contain a valid pair of eyes. Eyes can be marked as : or ;
-A smiley face can have a nose but it does not have to. Valid characters for a nose are - or ~
-Every smiling face must have a smiling mouth that should be marked with either ) or D. -
break_camelCase: The function will break up camel casing, using a space between words. For example 'camelCasing' returns 'camel Casing'
- creditCard_mask: The function maskify, changes all but the last four characters into '#'. For example '4556364607935616' returns '############5616'
- pileOfCubes: We pass a variable m as an argument and the function will return n if it exists and -1 if it doesn't exist such that m = n^3 + (n-1)^3 + ... + 1^3. Basically, m represents total voloume of building and n represents total pile of cubes placed one over another to form the building.
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steps_in_prime: This function returns the first pair of the two prime numbers spaced with a step of g between the limits m, n if these g-steps prime numbers exists otherwise nil.
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sum_of_sequence_1: This function returns the sum of a sequence of integers. The sequence is defined by 3 non-negative values: begin, end, step. If begin value is greater than the end, function should returns 0
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dont_give_5: The start number and the end number of a region is given as parameter of the function which returns the count of all numbers except numbers with a 5 in it. The start and the end number are both inclusive.
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sort_inner_letters: The function sorts the inner content of every word of a string in descending order. The inner content is the content of a word without first and the last char.
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are_they_same: Given two arrays a and b, the function comp(a, b) checks whether the two arrays have the "same" elements, with the same multiplicities. "Same" means, here, that the elements in b are the elements in a squared, regardless of the order.
- decrypt: An unscramble string is passed as encrypted message to the function. Each message is a single string, with the blocks for each letter separated by a space. The blocks encoding the characters are made up of seemingly random characters and are of a variable length. For example, a two character word might look like: "x206< y_r9L" To decode this string, this is what the function does :
sum of integers in "x206<" --> 2 + 0 + 6 = 8
sum of integers in "y_r9L" --> 9
Then maps these numbers to the corresponding letters of the alphabet, with 0 representing a space, 1 representing 'a', 2 representing a 'b' and so on.
So we have: "x20*6< y_r9L" --> "8 9" --> "hi"
Also, if the sum of the digits goes over 26, it loops back to zero (standard modulo / remainder function, such that 27 == 0, 28 == 1, etc.).
Phew, it was tough.
- sort_twisted37: The function takes an random array and sorts it taking 3 as 7 and 7 as 3. For example :
[1,2,3,4,5,6,7,8,9] -> [1,2,7,4,5,6,3,8,9]
[12,13,14] -> [12,14,13]
[9,2,4,7,3] -> [2,7,4,3,9]
This was crazy tough :v
- split_even_numbers: It has a very long description so refer to this page.
- find_the_divisors: The function takes an integer and returns an array with all of the integer's divisors(except for 1 and the number itself). If the number is prime, it returns the string '(integer) is prime'
- modulo_3_sequence: Consider a sequence where the first two numbers are 0 and 1 and the next number of the sequence is the sum of the previous 2 modulo 3. The function finds the nth number of the sequence.
- prize_draw: It has a very long description so refer to this page.
- sum_without_highlow: A function that returns the sum of all the integers of an array except the highest and the lowest integer. It returns 0 if the array is nill or empty or just has 1 or 2 elements.
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find_missing_letters: The method takes an array of consecutive (increasing) letters as input and that returns the missing letter in the array.
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the_sceptical_kid_generator: The function 'AlanAnnoyingKid' takes as input a sentence spoken by Alan (a string). The sentence contains the following structure:
"Today I " + [action_verb] + [object] + "."
(e.g.: "Today I played football.")
The function will return Alan's kid response, which is another sentence with the following structure:
"I don't think you " + [action_performed_by_alan] + " today, I think you " + ["did" OR "didn't"] + [verb_of _action_in_present_tense] + [" it!" OR " at all!"]
(e.g.:"I don't think you played football today, I think you didn't play at all!")
- length_of_missing_array: An array is supplied. If you sort the arrays by their length, you will see, that their length-values are consecutive. But one array is missing! The method, returns the length of the missing array. If the array of arrays is null/nil or empty, the method returns 0. When an array in the array is null or empty, the method returns 0 too!
- fold_array: The method folds a given array of integers by the middle x-times. For example when [1,2,3,4,5] is folded 1 times, it gives [6,6,3] and when folded two times it gives [9,6]. For more information click here
- tortoise_racing: Two tortoises named A and B must run a race. A starts with an average speed of 720 feet per hour. Young B knows she runs faster than A and furthermore has not finished her cabbage. When she starts, at last, she can see that A has a 70 feet lead but B speed is 850 feet per hour. How long will it take B to catch A? More generally: given two speeds v1 (A speed, integer > 0) and v2 (B speed, integer > 0) and a lead g (integer > 0) how long will it take B to catch A? The result will be an array [h, mn, s] where h, mn, s is the time needed in hours, minutes and seconds. The two speeds and lead will be given.
- disemvowel_trolls: Trolls are attacking your comment section!. A common way to deal with this situation is to remove all of the vowels from the trolls' comments, neutralizing the threat. The function that takes a string and return a new string with all vowels removed. For example, the string "This website is for losers LOL!" would become "Ths wbst s fr lsrs LL!".
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backward_read_primes: The function finds all Backwards Read Primes between two positive given numbers (both inclusive), the second one being greater than the first one. The resulting array or the resulting string will be ordered following the natural order of the prime numbers.
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cut_the_ropes: N ropes are given , where the length of each rope is a positive integer. At each step, the function reduces all the ropes by the length of the smallest rope. The step will be repeated until no ropes are left. Given the length of N ropes in an array, the function returns the number of ropes that are left before each step in an array. For more information click here
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rectangle_into_square: Description can be found here
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cut_array_into_small_parts: The function makeParts takes an array as argument and the size of the chunk. Example: if an array of size 123 is given and chunk size is 10 there will be 13 parts, 12 of size 10 and 1 of size 3.
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batman_quotes: Description can be found here
- rearange_to_max: The function takes one positive three digit integer and rearanges its digits to get maximum possible number. The argument is integer. It returns nil if argument is not valid.
- shortest_word: Given a string of words, the function returns the length of the shortest word(s). String should not be empty.
- the_oldest_ages: The two oldest ages function/method needs to be completed. It takes an array of numbers as its argument and returns the two highest numbers within the array. The returned value will be be an array in the format [second oldest age, oldest age].
- sum_of_numbers: The function computes the series starting from 0 and ending until the given number and finally returns a string in the following format :
"0+1+2+...n = sum "
- count_in_matrix: The function count_number(n, x) will count the number of x present in a matrix of size nXn where the value of each element of the matrix is the product of the index of its row and columns ie iXj
- mod256_without_mod: The function returns the remainder of a number when divided by 256 without using mod operator.
- rank_of_element: Given an array arr, the function finds the rank of the element at the ith position.The rank of the arr[i] is a value equal to the number of elements less than or equal to arr[i] standing before arr[i], plus the number of elements less than arr[i] standing after arr[i].
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get_middle_char: The function takes a word as a string and returns the middle character of the word. If the word's length is odd, it returns the middle character. If the word's length is even, it returns the middle 2 characters.
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complimentary_DNA: In DNA strings, symbols "A" and "T" are complements of each other, as "C" and "G". The function takes one side of the DNA (string, except for Haskell); and returns the other complementary side. DNA strand is never empty or there is no DNA at all.
- array_packing: An array of up to four non-negative integers is given, each less than 256. The function packs these integers into one number M in this way: "The first element of the array occupies the first 8 bits of M. The second element occupies next 8 bits, and so on." and returns the obtained integer M as unsigned integer.
- mumbling: The function does the following :
accum("abcd") --> "A-Bb-Ccc-Dddd"
accum("RqaEzty") --> "R-Qq-Aaa-Eeee-Zzzzz-Tttttt-Yyyyyyy"
accum("cwAt") --> "C-Ww-Aaa-Tttt"
- new_numerical_system: Your Informatics teacher at school likes coming up with new ways to help you understand the material. When you started studying numeral systems, he introduced his own numeral system, which he's convinced will help clarify things. His numeral system has base 26, and its digits are represented by English capital letters - A for 0, B for 1, and so on. The teacher assigned you the following numeral system exercise: given a one-digit number, you should find all unordered pairs of one-digit numbers whose values add up to the number. For example for input "G" the function returns ["A + G", "B + F", "C + E", "D + D"].
- valid_number: Congratulations! That Special Someone has given you their phone number. But WAIT, is it a valid number? The function verifies whether the given string contains a valid British mobile (cell) phone number or not. If valid, it returns 'In with a chance'. If invalid, or if given an empty string, it returns 'Plenty more fish in the sea'. A number can be valid in the following ways: In the UK, mobile numbers begin with '07' followed by 9 other digits, e.g. '07454876120'. Sometimes the number is preceded by the country code, the prefix '+44', which replaces the '0' in ‘07’, e.g. '+447454876120'. And sometimes numbers are given with dashes in-between digits or on either side, e.g. '+44--745---487-6120' or '-074-54-87-61-20-'.
- jaden_casing_string: Jaden Smith, the son of Will Smith, is the star of films such as The Karate Kid (2010) and After Earth (2013). When Jaden writes on Twitter, he is known for almost always capitalizing every word. The program converts strings to how they would be written by Jaden Smith.
- reverse_and_invert: The function reverses and inverts all integer values in a given array and ignores all other types than integer.
- stack_array: Stack implementation using array in C++. It contains functions like push, pop and display for a stack which can hold up to 5 integer values.
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tribonacci_series: Given the first three terms of the tribonacce series as an array and a non negative integer n, the function returns the first n elements of the series as an array.
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Xbonacci_series: This is a Xbonacci function that takes a signature of X elements - and each next element is the sum of the last X elements - and returns the first n elements of the so seeded sequence.
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alphabet_war: Description can be found here
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covfefe: Given a string. The program must replace the word(s) coverage by covfefe, however, if it doesn't find the word coverage in the string, it must add covfefe at the end of the string with a leading space.
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lost_number: An ordered sequence of numbers from 1 to N is given. One number might have deleted from it, then the remaining numbers were mixed. The method finds the number that was deleted.
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english beggars: Given an array of values and an amount of beggars, the function returns an array with the sum of what each beggar brings home, assuming they all take regular turns, from the first to the last. For, for example: [1,2,3,4,5] for 2 beggars will return a result of [9,6], as the first one takes [1,3,5], the second collects [2,4].