03. House Party

function houseParty(arr) {
    let guests = [];
    while (arr.length !== 0){
        let guest = arr.shift().split(' ');

        if (guest.length === 3){
            if (guests.includes(guest[0])){
                console.log(`${guest[0]} is already in the list!`)
            } else {
                guests.push(guest[0]);
            }
        } else{
            if (!guests.includes(guest[0])){
                console.log(`${guest[0]} is not in the list!`)
            } else {
                guests.splice(guests.indexOf(guest[0]), 1);
            }
        }
    }
    console.log(guests.join('\n'));
}