title: Creating an encryption program in C++ by only using arrays. Not sure how to continue
body: <p>EDIT NOTE* I am not trying to create something to use. I am creating this to get a firm grasp on how arrays work in c++. </p>
  
  <p>Hello I am creating a simple encryption program. This is my first program (for fun) and I am a bit confused on how to go on with this.(I have some code, but boy am I stuck!)</p>
  
  <p>So, first of all, I am going to use the ROT-N encryption method.</p>
  
  <p>Basically I want the user to enter a message, and have the message obey these rules:</p>
  
  <p>1)  Shift every character/digit the user enters and shift it to the right 8-15 characters/digits, and have it loop around. I do not want to go into the extended characters list.</p>
  
  <p>2) If the user enters a lowercase letter, I want to make it become lowercase. </p>
  
  <p>3) Last bit - I want the spaces to be encrypted too. The program should point out where the spaces are.</p>
  
  <p>Ex. If user enters "Message 0600"</p>
  
  <p>The encrypted message should say "8umaaiom3933&amp;8"</p>
  
  <p>The "8" in the beginning says how much the letters are offset. The "umaaiom3933" is the encrypted message. The &amp; signifies that the message is over, and the last "8" signifies where the space is.</p>
  
  <p>What I am having trouble with:</p>
  
  <p>1)Trying to take the message from the user and putting it in a array (each character in the message becomes a character in the array)</p>
  
  <p>2) Taking those characters and adding the offset value for a different value</p>
  
  <p>This is what I have so far.</p>
  
  <pre><code>#include &lt;iostream&gt; 
  #include &lt;string&gt;
  #include &lt;cstdlib&gt;
  #include &lt;ctime&gt;
  using namespace std;
  
  int main()
  {
      srand(time(0));
      int n = 13;
      cout &lt;&lt; n &lt;&lt; endl;
      int r = n + 255;
      string mes, emes;
      cout &lt;&lt; "Please enter the message: " &lt;&lt; endl;
      getline(cin,mes);
      int len = mes.length();
      for(int i = 0; i &lt;= len; i++)
      {
          mes[i] += n;
      }
      cout &lt;&lt; mes;
  
  
  
  
  
      return 0;
  }
  </code></pre>