title: date format without leading zeros - R
body: <p>I have dates in a character vector and I'm looking for a way to transform it to date format with <code>as.Date()</code>:</p>
  
  <pre><code>vector &lt;- c("15/1/2019", "5/5/2019")
  </code></pre>
  
  <p>However, <code>as.Date(vector, format="%d/%m/%Y")</code> receives as input characters with zeros leading. And I have found plenty of solutions for:</p>
  
  <pre><code>Input: "15/01/2019"
  Output: "15/1/2019"
  </code></pre>
  
  <p>However, I need exactly the opposite to make <code>as.Date()</code> to work:</p>
  
  <pre><code>Input: "15/1/2019" "5/5/2019"
  Output: "15/01/2019" "05/05/2019"
  </code></pre>
  
  <p>Is there any specific formatting for <code>format</code> argument? Or I have to use a <code>substr()</code> solution?</p>