Since Cody is 5 years old, it's pernicious. A Pernicious number is an integer whose population count is a prime. Check if the given number is pernicious.
Solution Stats
Problem Comments
-
1 Comment
Marco
on 1 Jan 2018
Very interesting problem!
Solution Comments
-
1 Comment
A C
on 1 Aug 2018
% 22 (which is 10110 in binary) has a population count of 3,
% which is prime, and therefore 22 is a pernicious number.
-
1 Comment
Jafar Ala
on 30 Dec 2017
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?
-
1 Comment
Gaston Levannier
on 2 Nov 2017
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
-
3 Comments
Teodo
on 20 Oct 2017
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.
Teodo
on 20 Oct 2017
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...
David Verrelli
on 15 Nov 2017
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
-
2 Comments
Benjamin Siegl
on 18 Oct 2017
What is wrong with the command de2bi?
David Verrelli
on 19 Oct 2017
de2bi is a function in the Communications System Toolbox, which is not a core part of MATLAB, and is not included in Cody.
-
1 Comment
Lane Maxwell
on 9 Nov 2017
This solution will not work for all values of x, only those in the given test suite.
Recent Solvers630
Suggested Problems
-
Maximum running product for a string of numbers
703 Solvers
-
268 Solvers
-
852 Solvers
-
222 Solvers
-
183 Solvers
More from this Author47
Tags
Discover what MATLAB® can do for your career.
Opportunities for recent engineering grads.
Apply Today