Function Subtracts Two Nonnegative Integers

My task is to create a MATLAB function that subtracts two nonnegative integers. x, y, and x_minus_y are row vectors representing nonnegative integers. I have a program that works for most cases except for some such as 'ex6(7500,7499)'. I am not sure why the program is not working for this case. Here is what I have:

function x_minus_y = ex6(x,y)

%

%

x = [0 x];

xLength = length(x);

yLength = length(y);

y = [zeros(1, xLength - yLength), y];

x_minus_y = x - y;

for position = xLength:-1:2

if x_minus_y(position) < 9

x_minus_y(position) = x_minus_y(position) + 10;

x_minus_y(position - 1) = x_minus_y(position - 1) + 1;

end

end

if x_minus_y(1) = 0

x_minus_y = x_minus_y(2:end);

end

Answer 1

[Cris LaPierre]

For your if conditional, use two = for comparison.

if x_minus_y(1) == 0