OA: topological sorting:

http://lintcode.com/en/problem/topological-sorting/

OA: Longest Line of Consecutive One in Matrix:

https://leetcode.com/problems/longest-line-of-consecutive-one-in-matrix/description/

Similar questions:

Longest Increasing Continuous subsequence II

http://lintcode.com/en/problem/longest-increasing-continuous-subsequence-ii/