GeneticAlgorithms

An example of genetic algorithm.

The problem

Given the digits 0 through 9 and the operators +, -, * and /, find a sequence that will represent a given target number. The operators will be applied sequentially from left to right as you read.

So, given the target number 23, the sequence 6 + 5 * 4 / 2 + 1 would be one possible solution.

If 75.5 is the chosen number then 5 / 2 + 9 * 7 - 5 would be a possible solution.

More informations about the problem here.

The solution

Try it

To run the solution, you can do the following:

> chmod +x script.swift
> ./script.swift

Tweak it

You can change the different parameters of the compute function to have a better understanding of what is going on:

optimal: Value to find
dnaSize: Length of the solution
populationSize: Number of individuals in a population
generations: Number of generations created before calculating fitness on a population
mutationChance: Chance that the dna will mutate with each generation, 1 / mutationChance

References

The script is inspired from https://gist.github.com/blainerothrock/efda6e12fe10792c99c990f8ff3daeba