title: (C++) Reading digits from text file
body: <p>I have a text file which looks like this:</p>
  
  <blockquote>
    <p>73167176531330624919225119674426574742355349194934
    96983520312774506326239578318016984801869478851843
    85861560789112949495459501737958331952853208805511</p>
  </blockquote>
  
  <p>and etc. 20 lines in total.
  What I want to do is to read every digit from the text file and put them into an array of integers(one element = one digit). How can I read only one digit from this text file, not the whole line?</p>