title: How to get the shortest palindrome of a string
body: <p>For example :</p>
  
  <p>String is : abcd</p>
  
  <p>shortest palindrome is abcdcba is the solution</p>
  
  <p>longer palindrome can be : abcddcba </p>
  
  <p>another example:</p>
  
  <p>String : aaaab</p>
  
  <p>shortest palindrome is aaaabaaaa </p>
  
  <p>longer palindrome can be aaaaabbaaaa</p>
  
  <p>Restrictions : you can only add characters in the end.</p>