Solved problem 46.
Renamed a solution file to merge answers
Removed unnecessary a tuple for concise.
Solved problem 48 and adjusted .
Fixed a bug of  and solved problem 49.
Solved problem 50.
Used Data.Ord(comparing) to make code concise.
Solved problem 55.
Used
Solved problem 56.
Fixed not to check node value.
Fixed type of solution 56 and solved problem 57.
Solved problem 58.
Solved problem 59.
Added cbalTree with parameter: tree height.
Solved problem 60.
Reformed with point free style.
Renamed file to include implemented functions.
Solved problem 61.
Solved problem 61A.