# Rule 1: You cannot tell where a program is going to spend its time. Bottlenecks occur in surprising places, so do not try to second guess and put in a speed hack until you’ve proven that’s where the bottleneck is.
# Rule 2: Measure. Do not tune for speed until you have measured, and even then don’t unless one part of the code overwhelms the rest.
# Rule 3: Fancy algorithms are slow when n is small, and n is usually small. Fancy algorithms have big constants. Until you know that n is frequently going to be big, don’t get fancy. (Even if n does get big, use Rule 2 first.)
# Rule 4: Fancy algorithms are buggier than simple ones, and they are much harder to implement. Use simple algorithms as well as simple data structures.
# Rule 5: Data dominates. If you have chosen the right data structures and organized things well, the algorithms will almost always be self-evident. Data structures, not algorithms, are central to programming.
# Rule 6: There is no