Solved

Make a checkerboard matrix (★★★★★)
(copy of Prob. 4) Given an integer n, make an n-by-n matrix made up of alternating ones and zeros as shown below. The a(1...

6 months ago

Solved

Average of corner elements of a matrix (★★)
(copy of prob 2235) Calculate the average of corner elements of a matrix. e.g. x=[1 2 3; 4 5 6; 7 8 9;] avg = (1+3+7+9)...

6 months ago

Solved

Mo money, mo math #2! (★★★)
(adapted from Prob 9 Cody team) You have a matrix for which each row is a person and the columns represent the number of quar...

6 months ago

Solved

Mo money, mo math 1! (★★★)
(adapted from Prob 9 Cody team) You have a vector where the elements represent the number of $20 bills, $10 bills, $5 bills, ...

6 months ago

Solved

Sum of elements of a vector (★★★)
Given any vector x = [x1, x2, x3, ... xn], compute the sum of its elements. Thus, if x = [ 1 3 -2 5 ], then the sum of its el...

6 months ago

Solved

Triangle Numbers (★★)
(copy of problem 5) Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3...

6 months ago

Solved

Swap the first and last columns (★★)
(copy of Prob 19) Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becom...

6 months ago

Solved

Select every other element of a vector (★★)
(copy of prob 6) Write a function which returns every other element of the vector passed in. That is, it returns the all odd-...

6 months ago

Solved

Generate n equally spaced "intervals" between -x and x (★)
Given n and x, return a list of numbers (in ascending order) that divides the interval [-x x] into n equal-length intervals. ...

6 months ago

Solved

Create a vector with n repeated values of a number x (★★)
If x=3 and n=7 then the vector y would be y=[3 3 3 3 3 3 3]

6 months ago

Solved

Create logarithmically spaced values (★)
Given three numbers a,b,n with b>a, create a vector y with n logarithmic spaced values between 10^a and 10^b. Thus, if a = -2, ...

6 months ago

Solved

Doubling elements in a vector (★★)
(copy of prob. 1024) Given the vector A, return B in which all numbers in A are doubling. So for: A = [ 1 5 8 ] t...

6 months ago

Solved

Create a vector of n alternating ones and zeros (★★)
Given n, your output should be a vector y of numbers such that the first number is 1 and the numbers following it alternate betw...

6 months ago

Solved

Magnitude of a vector (★★★)
Given a vector x with values [ x1, x2, x3, ..., xn ], compute the magnitude (or length) of the vector which is given by href ...

6 months ago

Solved

Create a vector of the first n natural numbers (★)
If n = 7, your program should return a vector y, where y = [1 2 3 4 5 6 7].

6 months ago

Solved

Create a vector of the first n odd numbers (★)
If n = 10, your program should return a vector y, where y = [1 3 5 7 9 11 13 15 17 19].

6 months ago

Solved

Vector raised to a power, element-wise (★)
Given a vector A and a number x, raise each element of the vector to the power of x. Thus, if A = [2 5 7 1] and x = 0.5, then ...

6 months ago

Solved

Find the biggest empty box
You are given a matrix that contains only ones and zeros. Think of the ones as columns in an otherwise empty floor plan. You wan...

6 months ago

Solved

newRMS
find root mean square of a signal x in less time than the test code and accurate to six places.

6 months ago

Solved

Half?
If you toss an even number (x) of coins, what is the probability (y) of 50% head and 50% tail?

6 months ago

Solved

Person of interest?
given a person_of_interest, what is his_name?

6 months ago

Solved

List the complementary / symetric prime couples
Problem statement For a given positive integer n, provide the prime couples (p,p') such that p + p' = 10^n. NB : a number li...

7 months ago

Solved

Linear primes p' = mp + n
Problem statement List the prime numbers of the form p' = mp + n for a given (m,n) couple and such that p' < k, k positive in...

7 months ago

Solved

Check Legendre's conjecture
Context and problem statement Legendre's conjecture states for a given positive integer n, there always exists at least one pri...

7 months ago

Solved

List the twin prime couples
Problem statement The twin prime couples (p,p') are the ones such that p' = p + 2. For a given integer n > 1, list the twin p...

7 months ago

Solved

List the near-square primes, p = n² + 1 (Landau's 4th problem)
Historical context At the 1912 International Congress of Mathematicians, Edmund Landau listed four basic problems about prime...

7 months ago

Solved

List primes which are the sum of two consecutive lower primes plus minus one
Problem statement Some prime numbers can be written as the sum of two consecutive lower primes plus / minus one : Like t...

7 months ago

Solved

Check the integers additive decomposition conjecture
Problem statement A conjecture (I rediscovered ?) related to Goldbach's one states that every integer above 2 can be written ...

7 months ago

Solved

Euclid primes
Historical context Euclid, the greek mathematician proved at his time that the prime numbers set is an infinite. By the way he ...

7 months ago

Solved

Fermat primes
Historical context The french mathematician Pierre de Fermat found the formula to find some prime numbers. He thought / co...

7 months ago