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Remove the polynomials that have positive real elements of their roots.

The characteristic equation for a dynamic system is a polynomial whose roots indicate its behavior. If any of the <http://www.ma...

3 years ago

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Find state names that start with the letter N

Given a list of US states, remove all the states that start with the letter N. If s1 = 'Alabama Montana Nebraska Vermont Ne...

3 years ago

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It dseon't mettar waht oedrr the lrettes in a wrod are.

An internet meme from 2003 (read more <http://www.snopes.com/language/apocryph/cambridge.asp here>) asserted that readers are re...

3 years ago

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Remove the small words from a list of words.

Your job is to tidy up a list of words that appear in a string. The words are separated by one or more spaces. Remove all words ...

3 years ago

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Mandelbrot Numbers

The <http://en.wikipedia.org/wiki/Mandelbrot_set Mandelbrot Set> is built around a simple iterative equation. z(1) = c z...

3 years ago

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Prime factor digits

Consider the following number system. Calculate the prime factorization for each number n, then represent the prime factors in a...

3 years ago

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DNA N-Gram Distribution

Given a string s and a number n, find the most frequently occurring n-gram in the string, where the n-grams can begin at any poi...

3 years ago

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Counting in Finnish

Sort a vector of single digit whole numbers alphabetically by their name, in Finnish. See the Wikipedia page for <http://en.wik...

3 years ago

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Read a column of numbers and interpolate missing data

Given an input cell array of strings s, pick out the second column and turn it into a row vector of data. Missing data will be i...

3 years ago

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Kaprekar Steps

6174 is the <http://en.wikipedia.org/wiki/6174_%28number%29 Kaprekar constant>. All natural numbers less than 10,000 (except som...

3 years ago

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Find the two-word state names

Given a list of states, remove all the states that have two-word names. If s1 = 'Alabama Montana North Carolina Vermont N...

3 years ago

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Alphabetize by last name

Given a list of names in a cell array, sort the list by the last name. So if list = {'Barney Google','Snuffy Smith','Dagwood ...

3 years ago

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Find the peak 3n+1 sequence value

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...

3 years ago

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Word Counting and Indexing

You are given a list of strings, each being a list of words divided by spaces. Break the strings into words, then return a maste...

3 years ago

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Renaming a field in a structure array

MATLAB has a <http://www.mathworks.com/help/techdoc/ref/setfield.html setfield> and a <http://www.mathworks.com/help/techdoc/ref...

3 years ago

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Implement a ROT13 cipher

Replace each character in string s1 with the character that is shifted 13 positions from it (wrap back to the beginning if neces...

3 years ago

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Clean the List of Names

Given a list of names in a cell array, remove any duplications that result from different capitalizations of the same string. So...

3 years ago

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Find common elements in matrix rows

Given a matrix, find all elements that exist in every row. For example, given A = 1 2 3 5 9 2 5 9 3 2 5 9 ...

3 years 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...

3 years ago

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Encode Roman Numerals

Create a function taking a non-negative integer as its parameter and returning a string containing the Roman Numeral representat...

3 years ago

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The Goldbach Conjecture, Part 2

The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

3 years ago

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Find state names that end with the letter A

Given a list of US states, remove all the states that end with the letter A. Example: Input s1 = 'Alabama Montana Nebras...

3 years ago

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Indexed Probability Table

This question was inspired by a Stack Overflow question forwarded to me by Matt Simoneau. Given a vector x, make an indexed pro...

3 years ago

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Summing Digits within Text

Given a string with text and digits, add all the numbers together. Examples: Input str = '4 and 20 blackbirds baked in a...

3 years ago

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Pattern matching

Given a matrix, m-by-n, find all the rows that have the same "increase, decrease, or stay same" pattern going across the columns...

3 years ago

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Counting Sequence

Given a vector x, find the "counting sequence" y. A counting sequence is formed by "counting" the entries in a given sequence...

3 years ago

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Maximum running product for a string of numbers

Given a string s representing a list of numbers, find the five consecutive numbers that multiply to form the largest number. Spe...

3 years ago

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Duplicates

Write a function that accepts a cell array of strings and returns another cell array of strings *with only the duplicates* retai...

3 years 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, ...

3 years ago

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What is the next step in Conway's Life?

Given a matrix A that represents the state of <http://en.wikipedia.org/wiki/Conway's_Game_of_Life Conway's game of Life> at one ...

3 years ago