title: How can I find words in matrix of letters
body: <p>This is another question I was asked in the telephonic interview: </p>
  
  <p>Given a dictionary and a crossword(2d matrix of characters) find all the dictionary words which can be found in the crossword.</p>
  
  <p>All I could think of was hash the dictionary, find every possible word in the crossword and search the hash. I could not optimize it all.</p>
  
  <p>Must admit Microsoft interview questions are tough :(</p>
  
  <p>Please give me the lines to think on.</p>