Why is string comparison so fast in python?

Question

I became curious to understand the internals of how string comparison works in python when I was solving the following example algorithm problem:

Give

Answer 1

This is both implementation-dependent and hardware-dependent. Without knowing your target machine and specific distribution, I couldn't say for sure. However, I strongly suspect that the underlying hardware, like most, has memory block instructions. Among other things, this can compare a pair of arbitrarily long strings (up to addressing limits) in parallel and pipelined fashion. For instance, it may compare 8-byte slices at one slice per clock cycle. This is a lot faster than fiddling with byte-level indices.