bird-watcher.js

// @ts-check
//
// The line above enables type checking for this file. Various IDEs interpret
// the @ts-check directive. It will give you helpful autocompletion when
// implementing this exercise.

const WEEK_DAYS = 7

/**
 * Calculates the total bird count.
 *
 * @param {number[]} birdsPerDay
 * @returns {number} total bird count
 */
export function totalBirdCount(birdsPerDay) {
  let total = 0
  for (let i = 0; i < birdsPerDay.length; i++) {
    total += birdsPerDay[i]
  }
  return total
  // return birdsPerDay.reduce((x, y) => x + y, 0)
}

/**
 * Calculates the total number of birds seen in a specific week.
 *
 * @param {number[]} birdsPerDay
 * @param {number} week
 * @returns {number} birds counted in the given week
 */
export function birdsInWeek(birdsPerDay, week) {
  let total = 0
  const start = (week - 1) * WEEK_DAYS
  for (let i = start; i < start + WEEK_DAYS; i++) {
    total += birdsPerDay[i]
  }
  return total
  // return totalBirdCount(birdsPerDay.slice(start, start + WEEK_DAYS))
}

/**
 * Fixes the counting mistake by increasing the bird count
 * by one for every second day.
 *
 * @param {number[]} birdsPerDay
 * @returns {number[]} corrected bird count data
 */
export function fixBirdCountLog(birdsPerDay) {
  for (let i = 0; i < birdsPerDay.length; i++) {
    if ((i % 2) === 0) {
      birdsPerDay[i] = birdsPerDay[i] + 1
    }
  }
  return birdsPerDay
  // return birdsPerDay.map((b, i) => i % 2 === 0 ? b + 1 : b)
}