02. Treasure Hunt

function treasureHunt(input) {
    let chest = input.shift().split('|');

    while (true) {
        tokens = input.shift().split(' ');
        let command = tokens.shift();
        if (command === "Yohoho!") {
            break;
        } else if (command === "Loot") {
            for (let i = 0; i < tokens.length; i++) {
                if (!chest.includes(tokens[i])) {
                    chest.unshift(tokens[i]);
                }
            }
        } else if (command === "Drop") {
            let index = Number(tokens);
            if (index >= 0 && index < chest.length) {
                chest.push(chest.splice(index, 1));
            }
        } else if (command === "Steal") {
            let count = Number(tokens);
            let stolenChest = chest.splice(-count);
            console.log(stolenChest.join(", "));
        }
    }

    if (chest.length === 0) {
        console.log("Failed treasure hunt.");
    } else {
        console.log(`Average treasure gain: ${((chest.join('').length) / chest.length).toFixed(2)} pirate credits.`);
    }
    return;
}