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xinyu lei


36 total contributions since 2017

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Cell joiner
You are given a cell array of strings and a string delimiter. You need to produce one string which is composed of each string fr...

environ 2 ans ago

Solved


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...

environ 2 ans ago

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Nearest Numbers
Given a row vector of numbers, find the indices of the two nearest numbers. Examples: [index1 index2] = nearestNumbers([2 5 3...

environ 2 ans ago

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Bullseye Matrix
Given n (always odd), return output a that has concentric rings of the numbers 1 through (n+1)/2 around the center point. Exampl...

environ 2 ans ago

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Return the largest number that is adjacent to a zero
This example comes from Steve Eddins' blog: <http://blogs.mathworks.com/steve/2009/05/27/learning-lessons-from-a-one-liner/ Lear...

environ 2 ans ago

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Target sorting
Sort the given list of numbers |a| according to how far away each element is from the target value |t|. The result should return...

environ 2 ans ago

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

environ 2 ans ago

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Which values occur exactly three times?
Return a list of all values (sorted smallest to largest) that appear exactly three times in the input vector x. So if x = [1 2...

environ 2 ans ago

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Remove the vowels
Remove all the vowels in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill' Output s2 is 'Jck nd Jll wn...

environ 2 ans 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...

environ 2 ans ago

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Check if sorted
Check if sorted. Example: Input x = [1 2 0] Output y is 0

environ 2 ans 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 + ...

environ 2 ans ago

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Who Has the Most Change?
You have a matrix for which each row is a person and the columns represent the number of quarters, nickels, dimes, and pennies t...

environ 2 ans 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...

environ 2 ans ago

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Back and Forth Rows
Given a number n, create an n-by-n matrix in which the integers from 1 to n^2 wind back and forth along the rows as shown in the...

environ 2 ans ago

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Most nonzero elements in row
Given the matrix a, return the index r of the row with the most nonzero elements. Assume there will always be exactly one row th...

environ 2 ans 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...

environ 2 ans 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 other numbers. Otherwise return false. E...

environ 2 ans ago

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Remove any row in which a NaN appears
Given the matrix A, return B in which all the rows that have one or more <http://www.mathworks.com/help/techdoc/ref/nan.html NaN...

environ 2 ans 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...

environ 2 ans ago

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Weighted average
Given two lists of numbers, determine the weighted average. Example [1 2 3] and [10 15 20] should result in 33.333...

environ 2 ans 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...

environ 2 ans 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: Inpu...

environ 2 ans ago

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Swap the first and last columns
Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becomes the first. All oth...

environ 2 ans ago

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Make a checkerboard matrix
Given an integer n, make an n-by-n matrix made up of alternating ones and zeros as shown below. The a(1,1) should be 1. Examp...

environ 2 ans ago

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Column Removal
Remove the nth column from input matrix A and return the resulting matrix in output B. So if A = [1 2 3; 4 5 6]; and ...

environ 2 ans 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 ...

environ 2 ans 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 displa...

environ 2 ans ago

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Pizza!
Given a circular pizza with radius _z_ and thickness _a_, return the pizza's volume. [ _z_ is first input argument.] Non-scor...

environ 2 ans 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.

environ 2 ans ago

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