[Algorithm] 47 week(12.19 ~ 12.25) 3/3

332. Reconstruct Itinerary

var findItinerary = function(tickets) {
    const dict = {};
    const sortedTickets = tickets.sort();

    sortedTickets.forEach(([a, b]) => {
        dict[a] = [ ...(dict[a] ?? []) ,b];
    })

    for(let dep in dict){
        dict[dep].sort()
    }

    const result = [];

    const dfs = (ticket) => {
        while(dict[ticket]?.length > 0){
            dfs(dict[ticket].shift());
        }
        result.unshift(ticket);
    };

    dfs('JFK');

    return result;
};