title: Generate random numbers with normal distribution given the mean and the std.dev
body: <p>My question is the following. I have to generate numbers distributed in various way.
  I generated the numbers with <em>uniform distribution</em> between <code>1 and 400</code> with <code>rand()%400+1</code>.
  Then I have to generate numbers with <em>normal distribution</em> with mean <code>100</code> and std dev <code>20</code>.
  Do you know how to do that in <em>C++</em>?</p>
  
  <p>I know that random library exist, but I don't know how to use it. Do I have to download it? Should I have <em>C++11</em> in my compiler? I have <code>gcc</code> in windows and <code>g++</code> in ubuntu.</p>