title: R + combine a list of vectors into a single vector
body: <p>I have a single list of numeric vector and I want to combine them into one vector. But I am unable to do that. This list can have one element common across the list element. Final vector should not add them twice. Here is an example:</p>
  
  <pre><code>&gt;lst
  `1`
  [1] 1 2
  `2`
  [2] 2 4 5
  `3`
  [3] 5 9 1
  </code></pre>
  
  <p>I want final result as this</p>
  
  <pre><code>&gt;result
  [1] 1 2 4 5 9 1
  </code></pre>
  
  <p>I tried doing following things, without worrying about the repition:</p>
  
  <pre><code>&gt;vec&lt;-vector()
  &gt;sapply(lst, append,vec)
  </code></pre>
  
  <p>and</p>
  
  <pre><code>&gt;vec&lt;-vector()
  &gt;sapply(lst, c, vec)
  </code></pre>
  
  <p>None of them worked. Can someone help me on this?</p>
  
  <p>Thanks.</p>