guineaPig.js

function guineaPig(input) {
    let index = 0;
    let food = Number(input[index]) * 1000;
    index++;
    let hay = Number(input[index]) * 1000;
    index++;
    let cover = Number(input[index]) * 1000;
    index++;
    let weight = Number(input[index]) * 1000;
    index++;
    let dayCounter = 0;
    let goodsEnough = true;

    while (dayCounter < 30) {
        dayCounter++;
        if (food - 300 < 0) {
            goodsEnough = false;
            console.log("Merry must go to the pet store!");
            break;
        } else {
            food -= 300;
        }

        if (dayCounter % 2 === 0) {
            let hayNeeded = food * 0.05;

            if (hay - hayNeeded < 0) {
                goodsEnough = false;
                console.log("Merry must go to the pet store!");
                break;
            } else {
                hay -= hayNeeded;
            }
        }

        if (dayCounter % 3 === 0) {
            let coverNeeded = weight / 3;

            if (cover - coverNeeded < 0) {
                goodsEnough = false;
                console.log("Merry must go to the pet store!");
                break;
            } else {
                cover -= coverNeeded;
            }
        }
    }
    if (goodsEnough) {
        console.log(`Everything is fine! Puppy is happy! Food: ${(food / 1000).toFixed(2)}, Hay: ${(hay / 1000).toFixed(2)}, Cover: ${(cover / 1000).toFixed(2)}.`);
    }
}

guineaPig(["10",
    "5",
    "5.2",
    "1"]);
guineaPig(["1",
    "1.5",
    "3",
    "1.5"
]);
guineaPig(["9",
    "5",
    "5.2",
    "1"]);