title: Find common words from two files
body: <p>Given two files containing list of words(around million), We need to find out the words that are in common. </p>
  
  <p>Use Some efficient algorithm, also not enough memory availble(1 million, certainly not).. Some basic C Programming code, if possible, would help.</p>
  
  <p>The files are not sorted.. We can use some sort of algorithm... Please support it with basic code...</p>
  
  <p>Sorting the external file...... with minimum memory available,, how can it be implement with C programming.</p>
  
  <p>Anybody game for external sorting of a file... Please share some code for this.</p>