Solution 79
Halve execution time for p79
Halved execution time for p79 again
Solution 81
Work in progress: solution 82
Improved algorithm for solution 82
Problem 82: created matrix->tree fn
Bug fix: import file properly for problem 82
Improve performance of problem 82 by memoizing fn
Problem 82: 10x speed increase by replacing unvisited? fn with set/difference
Added timbre profiling library
Problem 82: break out expensive unvisited-neighbours fn for analysis