title: Meaning of `printf("%0*lld",k,r);`
body: <p>I saw this code somewhere</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  int main()
  {
      long long k=1,r=4;
      printf("%0*lld",k,r);
  }
  </code></pre>
  
  <p>What is the meaning of <code>%0*lld</code> and how are two variables used in this when we have one format specifier?</p>