I dont know where i was wrong

%I am doing project euler 8,this is my code

function y = euler008(x)
  x=num2str(x)
  d=[]
  for i=1:length(x)
      number = str2num(x(i:i+4))
      digits = num2str(number) - '0'
      d=[d prod(digits)]
  end
  y=max(d)
end

%i dont know why this code is wrong

Answer 1

[Nguyen Huy]

i have edited all these errors,but it get %Index exceeds matrix dimensions error

[Atsushi Ueno]

one more thing, indexing shall be within 1 to length(x), so length(x)+4 exceeds the matrix dimensions.

for i=1:length(x)-4

[Nguyen Huy]

oh,i forgot that,thanks u all

Answer 2

[Atsushi Ueno]

Project Euler: Problem 8, Find largest product in a large string of numbers - MATLAB Cody - MATLAB Central (mathworks.com)

There is a variable 'a' in caller workspase and a function euler008(a) is called, but argument in the function euler008(x) is 'x'.

number = str2num(a(i:i+4)

shall be changed to

number = str2num(x(i:i+4))

Also, you need adding missing parenthesis as the first answer.

Answer 3

[Atsushi Ueno]

You are trying to access to variable x's index from 1 (min) to length(x)+4 (max).

  for i=1:length(x)
      number = str2num(x(i:i+4))

The maximum index number of variable x has been exceeded. If you modify the code to the following, it will work correctly.

  for i=1:length(x)-4
      number = str2num(x(i:i+4))

Answer 4

[Atsushi Ueno]

Solve Problem - MATLAB Cody - MATLAB Central (mathworks.com)

>The large number will be given as a string, 1xn characters.

So, x=num2str(x) on 2nd line won't work correctly. It should be deleted.