How to convert flowchart to MATLAB code ?

Dear Sirs, please help me to convert this flowchart to MATLAB code.

I am facing some difficulties in loops I tried hard to solve it several times but I couldn't.

it is about inputting a number and printing out if it prime number or not.

I would appreciate it if you could help me with this.

[Steven Lord]

This sounds like a homework assignment. If it is, show us the code you've written to try to solve the problem and ask a specific question about where you're having difficulty and we may be able to provide some guidance.

If you aren't sure where to start because you're not familiar with how to write MATLAB code, I suggest you start with the free MATLAB Onramp tutorial to quickly learn the essentials of MATLAB.

If you aren't sure where to start because you're not familiar with the mathematics you'll need to solve the problem, I recommend asking your professor and/or teaching assistant for help.

If this isn't homework, use the isprime function.

[sony]

counter = 2;
num = 0;
i = mod(num, counter);

disp('Enter Number');
num = input('');

while (num <= 0)
    disp('Enter Number');
    num = input('');
end

if (mod(num, 2) == 0)
    disp('not prime number');
end

if (mod(num, counter) > 0)
    counter = counter + 1;
    if (i == 0)
        disp('prime number');
    end
end

I tried this but I am stuck in the second loop on how to do it.

before this, I tried 20 times or more.

sorry, I am a beginner.

thanks, a lot.

[sony]

% Prompt the user to enter a positive integer
n = input('Enter a positive integer: ');

% Initialize the flag variable
is_prime = true;

% Check if the entered number is 0 or 1
if (n == 0 || n == 1)
    is_prime = false;
end

% Check if the entered number is divisible by any number from 2 to n/2
for i = 2:n/2
    if (mod(n, i) == 0)
        is_prime = false;
        break;
    end
end

% Display the result
if (is_prime)
    disp([num2str(n), ' is a prime number']);
else
    disp([num2str(n), ' is not a prime number']);
end

I found this solution it be good and makes sense but I am wondering how to do it like the previous flowchart.

Answer 1

[Walter Roberson]

input

plus

mod

for

[sony]

Thanks a lot, it is really tools help.

Answer 2

[DGM]

This is what I was squatting on. It's not a literal interpretation of the flowchart, but there's no good reason to use a literal interpretation.

% don't harrass the user for inputs 
% unless you like collecting typos
N = 456156445111;

% use a flag instead of a scattered bunch of redundant disp() calls
% avoid entering the loop if at all possible
P = [2 3 5 7 11 13 17 19 23 29 31 37]; % known small primes (as many as you want)
if ismember(N,[1 P]) % is N a known small prime?
    nisprime = true;
elseif any(~mod(N,P)) % does N have known small prime factors?
    nisprime = false;
else % this is slow
    for C = 2:N-1
        if ~mod(N,C)
            nisprime = false;
            break;
        end
    end
    nisprime = true;
end

if nisprime
    disp('prime')
else
    disp('not prime')
end

There are plenty of better examples in other threads. I just figured I'd dump this so that I can delete my forum notes.