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Spot the First Occurrence of 5

This problem series invites you to solve two simple problems related to the integer NUMBER FIVE, in order to celebrate <http:// ...

3 years ago

Solved

Recaman Sequence - II

Take an arbitrary starting point as input and create Recaman Sequence. Then find the 1, return its index. For example: if n =...

3 years ago

Solved

Recaman Sequence - I

Recaman Sequence (A005132 - <http://oeis.org/A005132 - OEIS Link>) is defined as follow; seq(0) = 0; for n > 0, seq(n) ...

3 years ago

Solved

Sums of Multiple Pairs of Triangular Numbers

This is a follow-up to Problem 44289 - Find two triangular numbers whose sum is input. There are some numbers that are the su...

3 years ago

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Write c^3 as sum of two squares a^2+b^2

write c^3 as sum of two squares a^2+b^2. For example 5^3 = 2^2 + 11^2 5^3 = 5^2 + 10^2 10^3 = 10^2 + 30^2 10^3 = 1...

3 years ago

Solved

Predicting life and death of a memory-less light bulb

You have a light bulb that can fail any moment according to the exponential probability distribution. At any moment, the pro...

3 years ago

Solved

A Simple Tide Gauge with MATLAB

You are standing in a few inches of sea water on a beach. You are wondering whether the high tide is coming soon or it has ju...

3 years ago

Solved

Is it really a 5?

A number containing at least one five will be passed to your function, which must return true or false depending upon whether th...

3 years ago

Solved

Extra safe primes

Did you know that the number 5 is the first safe prime? A safe prime is a prime number that can be expressed as 2p+1, where p is...

3 years ago

Solved

Tick. Tock. Tick. Tock. Tick. Tock. Tick. Tock. Tick. Tock.

Submit your answer to this problem a multiple of 5 seconds after the hour. Your answer is irrelevant; the only thing that matte...

3 years ago

Solved

Pernicious Anniversary Problem

Since Cody is 5 years old, it's pernicious. <http://rosettacode.org/wiki/Pernicious_numbers Pernicious number> is an integer whi...

3 years ago

Solved

Pentagonal Numbers

Your function will receive a lower and upper bound. It should return all pentagonal numbers within that inclusive range in ascen...

3 years ago

Solved

Energy of a photon

Given the frequency F of a photon in giga hertz. Find energy E of this photon in giga electron volts. Assume h, Planck's ...

3 years ago

Solved

How to subtract?

* Imagine you need to subtract a few numbers using MATLAB. * You will not be using eval for this task. * Given two ASCII strin...

3 years ago

Solved

Sum all integers from 1 to 2^n

Given the number x, y must be the summation of all integers from 1 to 2^x. For instance if x=2 then y must be 1+2+3+4=10.

4 years ago

Solved

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...

4 years ago

Solved

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...

4 years ago

Solved

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:...

4 years ago

Solved

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...

5 years ago

Solved

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...

5 years ago

Solved

Weighted average

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

5 years 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...

5 years ago

Solved

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...

5 years ago

Solved

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...

5 years ago

Solved

Pizza!

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

5 years ago

Solved

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. Example...

5 years ago

Solved

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 ...

5 years ago

Solved

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...

5 years ago

Solved

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 ...

5 years ago