HouseParty (Petromir Logic)

houseParty = (input) => {
    let guests = [];
    while(input.length > 0) {
        let cmd = input.shift().split(' ');
        let index = guests.indexOf(cmd[0]);

        if(index !== -1) {
            console.log(`${cmd[0]} is ${cmd[2] === 'going!' ? 'already' : 'not'} in the list!`);
        } else {
            if(cmd[2] === 'going!') {
                guests.push(cmd[0]);
            } else {
                guests.splice(index, 1);
            }
        }
    }

    console.log(guests.join('\n'));
};