Problem 2736. Pernicious Anniversary Problem
Solution Stats
Problem Comments
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1 Comment
Very interesting problem!
Solution Comments
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1 Comment
% 22 (which is 10110 in binary) has a population count of 3,
% which is prime, and therefore 22 is a pernicious number.
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1 Comment
Why does the test suite shows true results for numbers that are not prime, i.e. the sum of digits of the given number is not prime?
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1 Comment
With my function and R2015B, it works so I don't understand:
function y = isPernicious(x)
%UNTITLED2 Summary of this function goes here
% Detailed explanation goes here
if(x == 1)
y = true;
else
if(mod(x,2) == 0)
y = false;
else
y = true; % PRIME
for k=3:2:x-2
if(mod(x,k) == 0)
y = false; % NOT PRIME
break;
end
end
end
end
end
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3 Comments
Have provided a working and tested solution (two lines of code...), within the limits of the 2736 problem. The (my) solution had passed the Test Suite (!) - all 10 of them (tested at R2016b). Now, asking myself: is this worth time and effort - regarding the solutions assessment method for ... speaking, atm, only about this problem/solution issue.
Exactly, having the same issue: de2bi.
Now, MATLAB is made for solving problems. If, You must solve problems, with "stone age" limitations, how efficient is that? I do have a work-around for de2bin command, but it is not ... rational... to invest time into.
Sorry Cody, but: Wish You sincerely a Happy Anniversary, but those and similar limitations are missing the point of why is MATLAB - in the first place, made. And, ruining the fun...
Hello, Teodo. Just because "de2bi" isn't available in Cody (because it's part of an optional Toolbox), that _doesn't_ mean that there isn't a corresponding command among the core MATLAB functions. You will find it by searching the documentation. —DIV
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2 Comments
What is wrong with the command de2bi?
de2bi is a function in the Communications System Toolbox, which is not a core part of MATLAB, and is not included in Cody.
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1 Comment
This solution will not work for all values of x, only those in the given test suite.
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