static string[] solution(string[,] tickets)
{
Cor[] ticket = new Cor[tickets.GetLength(0)];
for (int i = 0; i < tickets.GetLength(0); i++)
{
ticket[i].x = tickets[i, 0];
ticket[i].y = tickets[i, 1];
}
Array.Sort(ticket, delegate(Cor u, Cor v)
{
return(u.y.CompareTo(v.y));
});
Array.Sort(ticket, delegate(Cor u, Cor v)
{
return(u.x.CompareTo(v.x));
});
Array.Reverse(ticket);
Dictionary <string, List <string> > routes = new Dictionary <string, List <string> >();
for (int i = 0; i < ticket.GetLength(0); i++)
{
string t1 = ticket[i].x;
string t2 = ticket[i].y;
if (routes.ContainsKey(t1))
{
routes[t1].Add(t2);
}
else
{
routes[t1] = new List <string> {
t2
};
}
}
Stack <string> stack = new Stack <string>();
stack.Push("ICN");
List <string> ans = new List <string>();
while (stack.Count != 0)
{
string top = stack.Peek();
if (routes.ContainsKey(top) == false || routes[top].Count == 0)
{
ans.Add(stack.Pop());
}
else
{
stack.Push(routes[top][routes[top].Count - 1]);
routes[top].RemoveAt(routes[top].Count - 1);
}
}
string[] an = ans.ToArray();
Array.Reverse(an);
return(an);
}
