Gold Mine

function goldMine(input) {
    let index = 0;
    let locations = Number(input[index++]);

    for (let i = 0; i < locations; i++) {
        let averageGold = Number(input[index++]);
        let dayDigging = Number(input[index++]);
        let goldSum = 0;
        for (let j = 0; j < dayDigging; j++) {
            goldSum += Number(input[index++]);
        }

        if ((goldSum / dayDigging) >= averageGold) {
            console.log(`Good job! Average gold per day: ${(goldSum / dayDigging).toFixed(2)}.`)
        } else {
            console.log(`You need ${(averageGold - (goldSum / dayDigging)).toFixed(2)} gold.`)
        }
    }
}

Решение със shift():

function goldMine(input) {
    let locations = Number(input.shift());

    for ( let i = 0; i < locations; i++) {
        let averageGold = Number(input.shift());
        let dayDigging = Number(input.shift());
        let goldSum = 0;
        for (let j = 0; j < dayDigging; j++) {
            goldSum += Number(input.shift());
        }

        if ((goldSum / dayDigging) >= averageGold) {
            console.log(`Good job! Average gold per day: ${(goldSum / dayDigging).toFixed(2)}.`)
        } else {
            console.log(`You need ${(averageGold - (goldSum / dayDigging)).toFixed(2)} gold.`)
        }
    }
}