title: What is the C++ equivalent of Python's "in" operator?
body: <p>What is the C++ way of checking if an element is contained in an array/list, similar to what the <code>in</code> operator does in Python?</p>
  
  <pre><code>if x in arr:
      print "found"
  else
      print "not found"
  </code></pre>
  
  <p>How does the time complexity of the C++ equivalent compare to Python's <code>in</code> operator?</p>