Optimize Selection Methods

Improve time complexity and memory requirements of all the selection methods.

Some know improvements include:

- [ ] Use prefix array and binary search for roulette Wheel and rank based selection.

The issue names roulette-wheel and rank-based selection methods but does not identify files or tests. Start by locating all selection methods and measuring their current time and memory use. Done means improving the methods' complexity, including prefix-array and binary-search selection where appropriate, with coverage for the changed behavior.

Written by the indexing model from the issue text.