Longest Common Subsequence & Longest Common Substring
http://www.geeksforgeeks.org/dynamic-programming-set-4-longest-common-subsequence/
http://www.geeksforgeeks.org/longest-common-substring/
http://www.geeksforgeeks.org/dynamic-programming-set-4-longest-common-subsequence/
http://www.geeksforgeeks.org/longest-common-substring/