constructor(leaveEmpty) {

    this.runners = [];

    this.size = 100;

    if (!leaveEmpty) {

      for (let i = 0; i < this.size; i++) {

        this.runners[i] = new Runner();

      }

    }

  }

  mutate(inp) {

    inp.dna.actions[random(inp.dna.actions.length)];

  }

  crossover(parentA, parentB) {

    let newDNA = new DNA();

    let newActions = [];

    let firstParent;

    let secondParent;

​

    if (random(2) > 0.5) {

      firstParent = parentA;

      secondParent = parentB;

    } else {

      firstParent = parentB;

      secondParent = parentA;

    }

    for (let i = 0; i < lifespan; i++) {

      if (i > lifespan / 2) {

        newActions[i] = firstParent.dna.actions[i];

      } else {

        print(secondParent)

        newActions[i] = secondParent.dna.actions[i];

      }

    }

​

    newDNA.actions = newActions;

​

    let child = new Runner(newDNA);

    return child;

  }

​

  loop() {

    for (let runner of this.runners) {

      runner.loop();

    }

  }

​

  evaluate() {

    let newPopul = new Population(true);

    let pool = [];

    let newRunners = [];

​

    for (let i = 0; i < this.runners.length; i++) {

      this.runners[i].calcFit();

      for (let i = 0; i < int(this.runners[i].fitness * 1000); i++) {

        print(this.runners[i])

        pool.push(this.runners[i]);

      }

    }

​

    //crossover and mutation:

​

    for (let i = 0; i < this.size; i++) {

      let child;

      child = this.crossover(random(pool), random(pool));

      child = this.mutate(child);

      newRunners.push(child);

    }

​

    newPopul.runners = newRunners;

    return newPopul;

  }

}

​