Solved

The Goldbach Conjecture

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

9 mois ago

Solved

Making change

Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = ...

9 mois ago

Solved

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...

9 mois ago

Solved

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...

9 mois ago

Solved

Make a Palindrome Number

Some numbers like 323 are palindromes. Other numbers like 124 are not. But look what happens when we add that number to a revers...

9 mois ago

Solved

Subset Sum

Given a vector v of integers and an integer n, return the the indices of v (as a row vector in ascending order) that sum to n. I...

9 mois ago

Solved

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...

9 mois 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...

9 mois ago

Solved

Reverse Run-Length Encoder

Given a "counting sequence" vector x, construct the original sequence y. A counting sequence is formed by "counting" the entrie...

9 mois ago

Solved

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...

9 mois ago

Solved

Return a list sorted by number of occurrences

Given a vector x, return a vector y of the unique values in x sorted by the number of occurrences in x. Ties are resolved by a ...

9 mois 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...

9 mois ago

Solved

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...

9 mois 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 ...

9 mois ago

Solved

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...

9 mois ago

Solved

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...

9 mois ago

Solved

Tic Tac Toe FTW

Given a tic tac toe board: * 1 represents X * 0 represents empty. * -1 represents O It is X's move. If there is an imme...

9 mois ago

Solved

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...

9 mois ago

Solved

Nearest Numbers

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

9 mois 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...

9 mois ago

Problem

Matrix indexing with two vectors of indices (★★)

(copy of Prob 589) Given a matrix M and two index vectors a and b, return a row vector x where x(i) = M(a(i),b(i)). Thus, if...

9 mois ago | 0 | 25 solvers

Problem

Reindex a vector (★★)

(copy of Prob. 676) You are given two vectors of equal length. Vector N has numeric values (no Inf or NaN) while vector IDX h...

9 mois ago | 0 | 28 solvers

Problem

Get the elements of diagonal and antidiagonal for any m-by-n matrix (★★★★)

(copy of prob. 859) In this problem you must submit a solution which returns the diagonal and anti-diagonal elements without ...

9 mois ago | 0 | 21 solvers

Problem

Replicate elements in vectors (★★★)

(copy of Prob 867) Replicate each element of a row vector (with NaN) a constant number of times. Examples n=2, A=[1 2...

9 mois ago | 0 | 36 solvers

Problem

Remove the row average (★★★)

(copy of Prob. 963) Given a 2-d matrix, remove the row average from each row. Your solution MUST be vectorized. The solut...

9 mois ago | 2 | 26 solvers

Problem

Longest run of consecutive numbers (★★★★★)

(copy of Problem 672) Given a vector a, find the number(s) that is/are repeated consecutively most often. For example, if you...

9 mois ago | 1 | 31 solvers

Problem

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)...

9 mois ago | 0 | 62 solvers

Problem

Generate a vector which contains a pyramid pattern (★★★★)

Generate a vector that contains terms that follows a pyramid pattern up to the nth row: 1 2 2 3 3 3 4 4 4 4 ...

9 mois ago | 1 | 49 solvers

Problem

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...

9 mois ago | 0 | 66 solvers

Problem

Create times-tables (★★★)

(copy of prob 33) At one time or another, we all had to memorize boring times tables. 5 times 5 is 25. 5 times 6 is 30. 12 ti...

9 mois ago | 0 | 61 solvers