Tricks of type inference
Median of two sorted array
BFS and DFS version
Very nice solution

https://oj.leetcode.com/discuss/3745/solve-this-problem-with-binary-search
Very interesting problem!
Linear time solution
2nd visit of problem
Recursive solution
2nd visit
BFS
No optimization version
New util func
Better solution
New problem
Backup - revert not using A*
Still TLE on one case
Still TLE!
Tidy up solution
Add list
2nd visit