解決済み

Which permutation is it?
Let write some permutations of positive integers. 1: 1 2 3 4 5 6 ... 2: 2 1 3 4 ... 3: 1 3 2 4 ....

10ヶ月前

解決済み

N-th permutation.
Let write some permutations of positive integers. 1: 1 2 3 4 5 6 ... 2: 2 1 3 4 ... 3: 1 3 2 4 ... ...

10ヶ月前

解決済み

Diophantine Equations (Inspired by Project Euler, problem 66)
Consider the quadratic Diophantine equation of the form: x^2 – Dy^2 = 1 When D=13, the minimal solution in x is 649^2 – 13...

10ヶ月前

解決済み

High Precision Square Root (Inspired by Project Euler 80)
Given a positive integer n which is not a perfect square, write a MATLAB script that will calculate the square root of n truncat...

10ヶ月前

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Decrypt the cypher using XOR encryption (for beginners)
Inspired by Project Euler n°59 Each character on a computer is assigned a unique code and the preferred standard is ASCII (...

10ヶ月前

解決済み

I've got the power! (Inspired by Project Euler problem 29)
Consider all integer combinations of a^b and b^a for the integer values 2 ≤ a ≤ 4 and 2 ≤ b ≤ 5: 2^2=4, 2^3=8, 2^4=16,...

10ヶ月前

解決済み

Repopulate the City
For any population p of positive integers between pmin and pmax, we can calculate histogram count n for a list of evenly dividin...

11ヶ月前

解決済み

Compute the Lagarias Riemann Hypothesis sequence
Write a function that takes an input number and produces a sequence (i.e., all values up to and including the th value) compute...

11ヶ月前

解決済み

Compute the unitary totient of a number
The totient function , the subject of Cody Problems 656 and 50182, gives the number of integers smaller than that are relativel...

11ヶ月前

解決済み

List the nth term of Rozhenko’s inventory sequence
Consider a sequence constructed by repeated inventories. A new inventory begins each time a zero is encountered. The first few i...

11ヶ月前

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Count estrangements
Recently I made a puzzle for my wife that included a cryptogram, which involves an arrangement of the letters A through Z. I use...

11ヶ月前

解決済み

Trap a knight
Consider a knight on an infinite chessboard labeled with numbers spiraling outward. A knight starting on the square labeled 1 ca...

11ヶ月前

解決済み

Compute the Tetris sequence
In the Tetris sequence, which starts with a 1, the next term is the smallest positive integer not already in the sequence that h...

11ヶ月前

解決済み

Flip the parity of digits in a decimal expansion
The number 349 has the decimal expansion . If we change the even digits from positive to negative, then the number becomes 269 (...

11ヶ月前

解決済み

Compute the largest number with a given integer complexity
Cody Problems 42831 and 42834 ask us to compute integer complexity, the smallest number of 1s needed to construct a number with ...

11ヶ月前

解決済み

Sum the unitary divisors of a number
Cody Problems 1933 and 46898 deal with , the sum of divisors function. This problem deals with , the sum of unitary divisors fun...

11ヶ月前

解決済み

Count the unitary divisors of a number
Cody Problem 56738 asks for a list of the unitary divisors of a number. For this problem, write a function to count the unitary ...

11ヶ月前

解決済み

List numbers that are not squares
The numbers 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, etc. are not perfect squares. Write a function to list the th term in ...

11ヶ月前

解決済み

Count the peaceful queens
In a 5x5 chessboard with a queen of one color (white, say) on the perimeter, one can place 12 black queens on the board such tha...

11ヶ月前

解決済み

Generate the Figure-Figure sequence
After discussing Scott Kim’s FIGURE-FIGURE Figure (below) in Gödel, Escher, Bach, Douglas Hofstadter introduced an integer seque...

11ヶ月前

解決済み

Determine whether the input is an anagram number
In Cody Problem 44293, Mehmet OZC asks us to spell numbers as words. For example, 67 would be “sixty-seven” and 76 would be “sev...

11ヶ月前

解決済み

Compute a determinant
Write a function to compute the determinant of an x matrix with diagonal entries equal to an integer and other entries equal ...

11ヶ月前

解決済み

The sliding puzzle: 3D
This is an extension of problem 42842. In this case, the puzzle is three-dimensional and is of size 3x3x3. Of the 27 positions i...

1年以上前

解決済み

Tautology
Check if the given expression is always true. For example, the sentence '~(A & B) == (~A | ~B)' is always true. Chara...

1年以上前

解決済み

Is this a valid Tic Tac Toe State?
For the game of <https://en.wikipedia.org/wiki/Tic-tac-toe Tic Tac Toe> we will be storing the state of the game in a matrix M. ...

1年以上前

解決済み

Hexagonal numbers on a spiral matrix
Put hexagonal numbers in a ( m x m ) spiral matrix and return the sum of its diagonal elements. Formula of hexagonal numbers ...

1年以上前

解決済み

Digit concentration in Champernowne's constant
Consider the first 50 digits of Champernowne's constant 0.12345678910111213141516171819202122232425262728293... The...

1年以上前

解決済み

Ned's queens
A tribute to Cody's five-year anniversary should also celebrate the people behind Cody, and in this particular case, our illustr...

1年以上前

解決済み

Acid and water
⚖ ⚖ ⚖ ⚖ ⚖ ⚖ ⚖ ⚖ Assume that there is a 100 liter tank. It is initially fi...

1年以上前

解決済み

The 5th Root
Write a function to find the 5th root of a number. It sounds easy, but the typical functions are not allowed (see the test su...

1年以上前