hackerRank viral advertising

// https://www.hackerrank.com/challenges/strange-advertising/problem

// declarative
const viralAdvertising = n => (
  Array.from(Array(n))
    .reduce((days, _, i) => days.concat(i + 1), [])
    .reduce((dailyLikeTotal, day) => (
      day === 1
        ? dailyLikeTotal.concat(2)
        : dailyLikeTotal.concat(Math.floor((dailyLikeTotal[dailyLikeTotal.length - 1] * 3) / 2))
    ), [])
    .reduce((totalLikes, dailyLikes) => totalLikes + dailyLikes)
)

// imperative
function viralAdvertising(n) {
    let peopleWhoLikeIt = [];
    for (let i = 1; i <= n; i++) {
        if (i === 1) {
            peopleWhoLikeIt.push(2);
        } else {
            peopleWhoLikeIt.push(Math.floor((peopleWhoLikeIt[peopleWhoLikeIt.length - 1] * 3) / 2))
        }
    }

    let total = 0;
    for (let i = 0; i < peopleWhoLikeIt.length; i++) {
        total = total + peopleWhoLikeIt[i];
    }
    return total;
}