Joshua

Last seen: 10 days ago | Active since 2026

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Remove all the consonants
Remove all the consonants in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill'; Output s2 is 'a ...

10 days ago

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Quote Doubler
Given a string s1, find all occurrences of the single quote character and replace them with two occurrences of the single quote ...

10 days ago

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Get the area codes from a list of phone numbers
Given a string of text with phone numbers in it, return a unique'd cell array of strings that are the area codes. s = '508-647...

10 days ago

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Find the two most distant points
Given a collection of points, return the indices of the rows that contain the two points most distant from one another. The inpu...

4 months ago

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Which doors are open?
There are n doors in an alley. Initially they are all shut. You have been tasked to go down the alley n times, and open/shut the...

4 months ago

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Elapsed Time
Given two date strings d1 and d2 of the form yyyy/mm/dd HH:MM:SS (assume hours HH is in 24 hour mode), determine how much time, ...

4 months ago

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Interpolator
You have a two vectors, a and b. They are monotonic and the same length. Given a value, va, where va is between a(1) and a(end),...

5 months ago

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Finding Perfect Squares
Given a vector of numbers, return true if one of the numbers is a square of one of the numbers. Otherwise return false. Example...

7 months ago

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Find the alphabetic word product
If the input string s is a word like 'hello', then the output word product p is a number based on the correspondence a=1, b=2, ....

7 months ago

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Knight's Tour Checker
Given a matrix a, determine whether or not a legal <http://en.wikipedia.org/wiki/Knight's_tour knight's tour> is present. The kn...

7 months ago

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Convert a grayscale image into RGB colour format, preserving data type
In the Image Processing Toolbox, MATLAB provides rgb2gray to convert a 3 channel color image into a 1 channel intensity...

8 months ago

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Pascal's Triangle
Given an integer n >= 0, generate the length n+1 row vector representing the n-th row of <http://en.wikipedia.org/wiki/Pascals_t...

8 months ago

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Return the 3n+1 sequence for n
A Collatz sequence is the sequence where, for a given number n, the next number in the sequence is either n/2 if the number is e...

8 months ago

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Determine whether a vector is monotonically increasing
Return true if the elements of the input vector increase monotonically (i.e. each element is larger than the previous). Return f...

8 months ago

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Sort a list of complex numbers based on far they are from the origin.
Given a list of complex numbers z, return a list zSorted such that the numbers that are farthest from the origin (0+0i) appear f...

9 months ago

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Summing digits
Given n, find the sum of the digits that make up 2^n. Example: Input n = 7 Output b = 11 since 2^7 = 128, and 1 + ...

9 months ago

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De-dupe
Remove all the redundant elements in a vector, but keep the first occurrence of each value in its original location. So if a =...

9 months ago

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Counting Money
Add the numbers given in the cell array of strings. The strings represent amounts of money using this notation: $99,999.99. E...

9 months ago

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Fibonacci sequence
Calculate the nth Fibonacci number. Given n, return f where f = fib(n) and f(1) = 1, f(2) = 1, f(3) = 2, ... Examples: Input...

9 months ago

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Create times-tables
At one time or another, we all had to memorize boring times tables. 5 times 5 is 25. 5 times 6 is 30. 12 times 12 is way more th...

9 months ago

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Find the numeric mean of the prime numbers in a matrix.
There will always be at least one prime in the matrix. Example: Input in = [ 8 3 5 9 ] Output out is 4...

9 months ago

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Find all elements less than 0 or greater than 10 and replace them with NaN
Given an input vector x, find all elements of x less than 0 or greater than 10 and replace them with NaN. Example: Input ...

9 months ago

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Select every other element of a vector
Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

9 months ago

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Determine if input is odd
Given the input n, return true if n is odd or false if n is even.

9 months ago

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Triangle Numbers
Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3 which can be displayed ...

9 months ago

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Add two numbers
Given a and b, return the sum a+b in c.

9 months ago

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Find the sum of all the numbers of the input vector
Find the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...

9 months ago

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Make the vector [1 2 3 4 5 6 7 8 9 10]
In MATLAB, you create a vector by enclosing the elements in square brackets like so: x = [1 2 3 4] Commas are optional, s...

9 months ago

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Times 2 - START HERE
Try out this test problem first. Given the variable x as your input, multiply it by two and put the result in y. Examples:...

9 months ago