Can someone check it for me ?

Write a program to find the first odd integer whose cube is greater than an integer entered by the user.

This is how far I got but it's working for some numbers however for some it's not

Can you check or tell me what did I do wrong ?

%MATLAB Programming Problem 22
int = input('Please input an integer: ');
%If the integer input integer is even, add 1
cube = int.^(1/3);
if cube > int^(1/3);
    cube = cube + 0;
else
    cube = cube + 2;
end
if rem(cube, 2) == 0
    cube = cube + 1;
else
    cube = cube + 0;
end
fprintf('The first odd integer is %1.0f\n', cube)

Answer 1

[Walter Roberson]

You define

cube = int.^(1/3)

and then in the next line compare

cube > int^(1/3)

so you are logically comparing

int^(1/3) > int^(1/3)

and logically speaking that is going to always be false. A test that is always false is seldom worth coding.

I did say "logically speaking" though. Real computations with floating point numbers are such that if you calculate an expression in two different but algebraically identical ways, the results are not necessarily going to be exactly the same. But which one would come out higher or lower is quite tricky to predict. It is possible in real computer languages for the test you created to turn out true, and you would have a difficult time figuring out the circumstances in advance.

So, whatever it is you think you are testing there, you'd better test it more robustly.

[Greg Heath]

help int

help ceil

Hope this helps

Greg