title: Can source string be converted to destination string?
body: <p>Is there a sequence of transformation steps to convert given source string to destination string?</p>
  
  <p>Note: At every step, one character can be transformed (replacement should be a character between 'A'-'Z') and all the occurrences of that character have to be transformed.
  Examples are given below.</p>
  
  <pre><code>Source: "ABA" 
  Dest: "BAB" 
  Output: True 
  Explanation: ABA -&gt; A**C**A -&gt; **B**C**B** -&gt; B**A**B 
  
  Source: "AA" 
  Dest: "BC" 
  Output: False 
  Explanation: AA -&gt; BB
  </code></pre>
  
  <p>I think <code>HashMap</code> works. But is there another Data Structure where I don't go about comparing Character by Character?</p>