04. Clever Lily

function cleverLily(input) {
    let age = Number(input[0]);
    let machine = Number(input[1]);
    let toyPrice = Number(input[2]);
    let sum = 0;
    let toy = 0;
    let birthday = 10;

    for (let i = 3; i < age + 3; i++) {
        if (i % 2 === 0) {
            sum += birthday - 1;
            birthday += 10;
        } else {
            toy++;
        }
    }
    sum += toy * toyPrice;

    if (sum >= machine) {
        console.log(`Yes! ${(sum - machine).toFixed(2)}`);
    } else {
        console.log(`No! ${(machine - sum).toFixed(2)}`);
    }
}

Решение с тернарен оператор леко тарикатската:

function cleverLily(input) {
    let age = Number(input[0]);
    let machine = Number(input[1]);
    let toyPrice = Number(input[2]);

    for (let i = 1; i <= age; i++) {
        machine -= i % 2 == 0 ? 5 * i - 1 : toyPrice
    }

    console.log(`${machine > 0 ? "No" : "Yes"}! ${Math.abs(machine).toFixed(2)}`);
}