title: Error QApplication: no such file or directory
body: <p>I have installed C++SDK that have Qt but when I try compiling a code linking QApplication it gives me the error:</p>
  
  <pre><code>Error QApplication: no such file or directory
  </code></pre>
  
  <p>How do I link these libraries? I searched into the directories and there is a file named QApplication.h; So I tried to link it with -I (linking the directory) but it was still giving me that error.</p>