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# Tim

Last seen: Today Active since 2012

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Chain multiplication - 03
Following up the problem in 55305, you found the minimum number of multiplications needed to multiply a chain of matrices. In ...

1 giorno ago

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Chain multiplication - 02
Following up on the problem in 55295, you found the number of multiplications needed to multiply two matrices. Now, you are giv...

1 giorno ago

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Cut the rod
A rod of length n can be cut in different sizes. Different price is associated with different length of cuts. length, len= [1,...

1 giorno ago

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Sort Non-zeros
Consider 0s in a vector creates a break-point. sort all the sub-arrays created by those break points. For example, a = [3, 4, 1...

3 giorni ago

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Chain multiplication - 01
Say, you are given two matrices - A (shape= 3*4) and B(shape = 4*5). If you multiply these two matrices, the resultant matrix w...

3 giorni ago

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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...

8 giorni ago

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Determine whether one vector is a subset of another
While bumbling through a pair of problems in the Number Theory group, I wrote code to determine whether a vector is a subset of ...

16 giorni ago

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Cyclotomic polynomial
Given a Natural number (N), return the corresponding Cyclotomic Polynomial.

16 giorni ago

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Parametric Array
Create a row vector, 1xN (Integer, >1), such that the mean of the vector is M (Real number) and the standard deviation of the ...

16 giorni ago

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List the semiprimes
A semiprime number—or a 2-almost prime—is the product of two prime numbers. The numbers and are semiprimes, but and are not....

17 giorni ago

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Nuemann Polynomials
Return the coefficients of nth (n>=0) Nuemann polynomial, (a sequence in 1/t) as polynomials in alpha. The expected output is a...

23 giorni ago

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Scorer's Function
Evaluate the Scorer's function for a given input. The expected output is Gi(x). Note - The precision will vary for test cases...

30 giorni ago

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B-Zuckerman Numbers
Similar to my last problem (B_Harshad Numbers), B-Zuckerman Numbers are numbers that are divisable by the product of their digit...

circa un mese ago

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Determine (and provide as output in decimal form) all the harshad numbers base B (B-Harshad) from a given array of decimal numbe...

circa un mese ago

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Distance walked 1D
Suppose you go from position 7 to 10 to 6 to 4. Then you have walked 9 units of distance, since 7 to 10 is 3 units, 10 to 6 is 4...

circa un mese ago

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Consecutive Pairs of Smooth Numbers from Set of Prime Numbers
Given an input set of prime numbers (p), generate all pairs of consecutive smooth numbers (x) (see Stormer's Theorem). For exam...

circa un mese ago

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

circa un mese ago

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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 (...

circa un mese ago

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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...

circa 2 mesi ago

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Hyperperfect Numbers
A k-hyperperfect number is a natural number n for which the equality n = 1 + k(σ(n) − n − 1) holds, where σ(n) is the divisor ...

circa 2 mesi ago

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Determine whether a number is practical
A number is practical if all smaller numbers can be written as a sum of the proper divisors of . The number 24 is practical bec...

circa 2 mesi ago

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List odd twin composites
Twin primes, or prime numbers that differ by 2 (e.g., 17 and 19, 59 and 61, or 191 and 193), are the subject of several Cody pro...

2 mesi ago

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Find the length of stream affected by a spill
When a contaminant is spilled into a stream, one might want to know how much of the stream is affected—e.g., the length over whi...

2 mesi ago

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Find the particular dividend
It is known that once you write the sequence 10101...101 long enough, the number will be finally divisible by any odd number if ...

2 mesi ago

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Count the ways to make Scorigami
Regarding the sport known as American football, some people are such rabid fans that they can tell you the statistics of every p...

2 mesi ago

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Solve an ODE: concentrations predicted by the cells-in-series model
One approach for predicting mixing and transport of contaminants in a river is the cells-in-series model. The model divides a ri...

2 mesi ago

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Local Extrema
Given a 2D (m,n>1) matrix, replace an element if it is not a local extrema (minima/maxima), with 0 (zero). The comparison crite...

2 mesi ago

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Chords form the basis of harmony in music. The most basic chords are triads, or groups of three notes. They are specified by thr...

2 mesi ago

Solved

Leyland Primes
A Leyland Number is defined as a number of the form - x^y + y^x, or, x^y - y^x (x,y)>1 Given an array of numbers(>1), check...

2 mesi ago

Solved

Compute the period of a pendulum started from a finite initial angle
Cody Problem 49830 asks for the period of a pendulum swinging through a small angle. Here the pendulum started at rest from an ...

2 mesi ago