title: Convert a string of characters string words[] to double feature[] in c++
body: <p>I read strings from a text file in my c++ script, those strings saved in <code>string words[3]</code> are in this form :</p>
  <pre><code>abc[1]
  abc[2]
  abc[3]*abc[2]
  </code></pre>
  <p>After reading those strings I want to convert <code>string words[3]</code> to <code>double feature[3]</code> in order to be able to replace those strings with the values of <code>double abc[3] = {1,2,3}</code>.
  So I want to get a <code>double feature[3] = {abc[1],abc[2],abc[3]*abc[2]}</code>
  How can I do this conversion in C++?</p>