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• Practice Challenges
• First Reverse

For this challenge you will be reversing a string. 141819 solutions

• First Factorial

For this challenge you will be determining the factorial for a given number. 124458 solutions

• Longest Word

For this challenge you will be determining the largest word in a string. 91138 solutions

• Letter Changes

For this challenge you will be manipulating characters in a string based off their positions in the alphabet. 89535 solutions

For this challenge you will be adding up all the numbers from 1 to a certain argument. 72758 solutions

• Letter Capitalize

For this challenge you will be capitalizing certain characters in a string. 61900 solutions

• Simple Symbols

For this challenge you will be determining whether or not certain characters are in correct positions. 52741 solutions

• Check Nums

For this challenge you will be comparing two numbers and determining which one is greater. 53176 solutions

• Time Convert

For this challenge you will be determining the difference in hours and minutes between two given times. 40749 solutions

• Alphabet Soup

For this challenge you will be sorting characters in a string. 37089 solutions

• AB Check

For this challenge you will determine if two characters are separated a specific way in the string. 17485 solutions

• Vowel Count

For this challenge you will be counting all the vowels in a string. 16057 solutions

• Word Count

For this challenge you will be determining how many words a sentence contains. 15111 solutions

• Ex Oh

For this challenge you will traverse a string and determine if there is an equal amount of certain characters. 14836 solutions

• Palindrome

For this challenge you will determine if a string is written the same way forward and backwards. 17288 solutions

• Arith Geo

For this challenge you will determine if numbers within an array follow an arithmetic or geometric sequence. 13827 solutions

• Array Addition I

For this challenge you will determine if numbers in an array can add up to a certain number in the array. 9000 solutions

• Letter Count I

For this challenge you will determine which word has the greatest number of repeated letters. 8205 solutions

• Second GreatLow

For this challenge you will determine the second lowest and greatest numbers in an array. 13577 solutions

• Division Stringified

For this challenge you will divide two numbers and return them in a certain format. 10115 solutions

• Counting Minutes I

For this challenge you will return the total number of minutes between two times. 6028 solutions

• Mean Mode

For this challenge you will determine if the mode equals the mean in an array. 7869 solutions

• Dash Insert

For this challenge you will be manipulating a string using dashes (-). 8960 solutions

• Swap Case

For this challenge you will be swapping the case of each character in the string. 8368 solutions

For this challenge you will traverse a string searching for all the numbers and then you will add them up. 8287 solutions

• Third Greatest

For this challenge you will determine the third largest string within an array. 7688 solutions

• Powers of Two

For this challenge you will be determining whether or not a number is a power of two. 8597 solutions

For this challenge you will be determining the additive persistence for a given number. 6138 solutions

• Multiplicative Persistence

For this challenge you will be determining the multiplicative persistence for a given number. 4724 solutions

• Off Line Minimum

For this challenge you will be creating a subset of an array. 6377 solutions

• Changing Sequence

For this challenge you will determine when an array changes sequences. 2748 solutions

• Overlapping Ranges

For this practice test you will determine the intersection between two sets. 2742 solutions

• Superincreasing

For this challenge you will determine if each number is greater than the sum of all previous elements in an array. 2804 solutions

• Hamming Distance

For this challenge you will determine the difference between two strings. 1960 solutions

• Rectangle Area

For this challenge you will determine the area of a rectangle. 2344 solutions

• Bitwise One

For this challenge you will perform a bitwise operation on two binary numbers. 1897 solutions

• Other Products

For this challenge you will return the product of a set of elements in an array. 1984 solutions

• Wave Sorting

For this challenge you will determine if numbers in an array can be sorted in a particular way. 1361 solutions

• Array Matching

For this challenge you will add elements from two arrays in a particular order. 1726 solutions

• Binary Reversal

For this challenge you will be reversing a binary string. 1454 solutions

• Longest Increasing Sequence

For this challenge you will compute the length of the longest increasing subsequence. 1435 solutions

• Even Pairs

For this challenge you will determine if a pair of even numbers exists somewhere in a string. 1298 solutions

• Next Palindrome

For this challenge you will be determining the next largest palindrome. 1136 solutions

• Largest Pair

For this challenge you will determine the largest double digit number. 1485 solutions

• Nonrepeating Character

For this challenge you will find the first non-repeating character in a string. 1239 solutions

• Two Sum

For this challenge you will determine if two elements can sum to some larger number. 2110 solutions

• Bitwise Two

For this challenge you will perform a bitwise operation on two binary numbers. 816 solutions

• Power Set Count

For this challenge you will determine the length of a power set. 1153 solutions

• Product Digits

For this challenge you will be determining the least amount of digits needed to produce a number. 1435 solutions

• Palindrome Creator

For this challenge you will be determining if you can create a palindrome from a list of numbers. 1375 solutions

• Basic Roman Numerals

For this challenge you will be converting a string of Roman numerals. 870 solutions

• Food Distribution

For this challenge you will determine how to optimally distribute food to people. 739 solutions

• Three Sum

For this challenge you will determine if three elements can sum to some larger number. 860 solutions

• Correct Path

For this challenge you will be traversing a matrix searching for the correct path to take. 2304 solutions

• Scale Balancing

For this challenge you will be balancing a scale with weights on it. 3255 solutions

• Three Numbers

For this challenge you will be searching for a set of numbers in a string. 832 solutions

• Alphabet Searching

For this challenge you will determine if a set of characters exists in a string. 713 solutions

• Time Difference

For this challenge you will be searching for the smallest time difference. 470 solutions

• Triangle Row

For this challenge you will be adding up a whole row from Pascal's triangle. 425 solutions

• Vowel Square

For this challenge you will determine if a square of vowels exists in a matrix. 2126 solutions

• Closest Enemy

For this challenge you will search in an array for an enemy. 675 solutions

• Closest Enemy II

For this challenge you will search in a matrix for an enemy. 2037 solutions

• Number Stream

For this challenge you will determine if a stream of digits occurs in a string. 460 solutions

• Largest Four

For this challenge you will need to find the four largest elements in an array. 769 solutions

• Distinct Characters

For this challenge you will determine if a string contains some number of distinct characters. 494 solutions

• Questions Marks

For this challenge you will be determining if a string follows a particular pattern. 5425 solutions

• Camel Case

For this challenge you will be converting a string into camel case format. 574 solutions

• ASCII Conversion

For this challenge you will be replacing certain characters in a string. 396 solutions

• Simple Evens

For this challenge you will be checking whether a number is even. 545 solutions

• Snake Case

For this challenge you will be converting a string into snake case format. 478 solutions

• Sum Multiplier

For this challenge you will determine if two numbers can be multiplied to some specific number. 578 solutions

• String Merge

For this challenge you will be merging two different strings together. 555 solutions

• One Decremented

For this challenge you will be counting how many times a specific pattern occurs in a large number. 507 solutions

• Element Merger

For this challenge you will be combining all of the elements in an array into a single number. 552 solutions

• GCF

For this challenge you will determine the greatest common factor of two numbers. 532 solutions

• Serial Number

For this challenge you will be determining if a string produces a valid serial number. 671 solutions

• String Periods

For this challenge you will need to find the smallest repeating substring. 578 solutions

• Palindrome Swapper

For this challenge you will determine if a palindrome can be created in a string. 397 solutions

• Remove Brackets

For this challenge you will determine how to create evenly matched brackets. 564 solutions

• Command Line

For this challenge you will be parsing a command line string and counting its characters. 263 solutions

• Star Rating

For this challenge you will be calculating how to display a 5 star rating. 580 solutions

• Moving Median

For this challenge you will calculate the median in an array within a sliding window. 241 solutions

• Group Totals

For this challenge you will be adding values from key, value pairs. 339 solutions

• String Changes

For this challenge you will manipulate a string based on two rules. 136 solutions

• FizzBuzz

For this challenge you will be solving the classic Fizz Buzz problem. 220 solutions

• H Distance

For this challenge you will determine the difference between two strings. 136 solutions

• Different Cases

For this challenge you will be converting a string into camel case format. 147 solutions