population.js

// create the initial population
let population = [];
for (let i = 0; i < POPULATION_SIZE; i++) {
  // generate a random individual
  let individual = [];
  for (let j = 0; j < NUM_CITIES; j++) {
    individual.push(j);
  }
  // shuffle the cities in the individual
  for (let j = 0; j < NUM_CITIES; j++) {
    let k = Math.floor(Math.random() * NUM_CITIES);
    let temp = individual[j];
    individual[j] = individual[k];
    individual[k] = temp;
  }
  population.push(individual);
}