- max sum of consecutive number in an array [5, -1, 3, -5, 2] => 5+-1+3=7 O(n) dp, O(n log n) divide and conquer
- Longest common substring in two string “abcdef” “ade” => “de” O(n^2) dp
- Longest common subsequence in two string “abcdef” “ade” => “ade” O(n^2) dp