07. Trekking Mania

function trekkingMania(input) {
    let groupNumbers = Number(input[0]);
    let musala = 0;
    let montBlanc = 0;
    let kilimanjaro = 0;
    let k2 = 0;
    let everest = 0;
    let alpinistSum = 0;

    for (let i = 1; i <= groupNumbers; i++) {
        let group = Number(input[i]);
        alpinistSum += group;
        if (group > 40) {
            everest += group;
        } else if (group > 25) {
            k2 += group;
        } else if (group > 12) {
            kilimanjaro += group;
        } else if (group > 5) {
            montBlanc += group;
        } else if (group > 0) {
            musala += group;
        }
    }

    console.log(`${(100.0 * musala / alpinistSum).toFixed(2)}%`);
    console.log(`${(100.0 * montBlanc / alpinistSum).toFixed(2)}%`);
    console.log(`${(100.0 * kilimanjaro / alpinistSum).toFixed(2)}%`);
    console.log(`${(100.0 * k2 / alpinistSum).toFixed(2)}%`);
    console.log(`${(100.0 * everest / alpinistSum).toFixed(2)}%`);
}

Решение с колекция, тернарен оператор и shift():

function trekkingMania(input) {
    let info = { 'musala': 0, 'montBlanc': 0, 'kilimanjaro': 0, 'k2': 0, 'everest': 0 };
    let groupNumbers = Number(input.shift());
    let alpinistSum = 0;

    while (groupNumbers-- !== 0) {
        let group = Number(input.shift());
        info[(group > 40 ? 'everest' : group > 25 ? 'k2' : group > 12 ? 'kilimanjaro' : group > 5 ? 'montBlanc' : 'musala')] += group;
        alpinistSum += group;
    }

    for (var mountain in info) {
        console.log(`${(100.0 * info[mountain] / alpinistSum).toFixed(2)}%`);
    }
}