Cody

Problem 1761. Primes Faster for Large N

Solution 2847453

Submitted on 18 Aug 2020 by pign_an
This solution is locked. To view this solution, you need to provide a solution of the same size or smaller.

Test Suite

Test Status Code Input and Output
1   Pass
tic assert(isequal(primes_faster(1),primes(1))) assert(isequal(primes_faster(2),primes(2))) for i=1:100 n=randi(2000,1); assert(isequal(primes_faster(n),primes(n))) end toc

Elapsed time is 0.026441 seconds.

2   Pass
tic ta=clock; p = primes_faster(2^28); t1=etime(clock,ta); % time in sec fprintf('P 2^28 %12i %10.3f\n',length(p),t1) assert(isequal(size(unique(p),2),14630843)) ptr=randi(7603553,1,10); % small to avoid timeout pchk=double(p(ptr)); assert(all(isprime(pchk))) feval( @assignin,'caller','score',floor(min(30,t1)) ); toc

P 2^28 14630843 4.558 Elapsed time is 4.865577 seconds.

Suggested Problems

More from this Author246

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!