static void Main(string[] args)
{
int n = int.Parse(Console.ReadLine());
int[] x = new int[n];
int[] y = new int[n];
for (int i = 0; i < n; i++)
{
string[] s = Console.ReadLine().Split(' ');
x[i] = int.Parse(s[0]);
//y[i] = int.Parse(s[1]);
//xy.Add(x[i], -int.Parse(s[1]));
//dict.Add(x[i], i + 1);
//ans.Add(i + 1, new vertex { });
}
Array.Sort(x);
/*for (int i = 0; i < n; i++)
* {
* y[i] = xy[x[i]];
* }*/
Treap myTreap = Treap.Build(x, y);
// Console.WriteLine("YES");
DFS(myTreap, null);
/* for (int i = 0; i < n; i++)
* {
* Console.WriteLine("{0} {1} {2}", ans[i + 1].parent, ans[i + 1].left, ans[i + 1].right);
* }*/
//Console.ReadKey();
}
public void Split(int x0, out Treap first, out Treap second)
{
Treap newTreap = null;
if (x <= x0)
{
if (right == null)
{
second = null;
}
else
{
right.Split(x0, out newTreap, out second);
}
first = new Treap(x, y, left, newTreap);
}
else
{
if (left == null)
{
first = null;
}
else
{
left.Split(x0, out first, out newTreap);
}
second = new Treap(x, y, newTreap, right);
}
}
public void Split(long x, out Treap L, out Treap R)
{
Treap newTree = null;
if (this.x <= x)
{
if (Right == null)
{
R = null;
}
else
{
Right.Split(x, out newTree, out R);
}
L = new Treap(this.x, y, Left, newTree);
}
else
{
if (Left == null)
{
L = null;
}
else
{
Left.Split(x, out L, out newTree);
}
R = new Treap(this.x, y, newTree, Right);
}
}
static void AddUnique(long x)
{
if (treap == null)
{
treap = new Treap(x, rnd.NextDouble());
}
else
{
Treap first, second, middle;
treap.Split(x - 1, out first, out second);
if (second != null)
{
second.Split(x, out middle, out second);
if (middle == null)
{
middle = new Treap(x, rnd.NextDouble());
treap = Treap.Merge(Treap.Merge(first, middle), second);
}
}
else
{
middle = new Treap(x, rnd.NextDouble());
treap = Treap.Merge(first, middle);
}
}
}
private Treap(int x, int y, Treap left = null, Treap right = null, Treap parent = null)
{
this.x = x;
this.y = y;
this.left = left;
this.right = right;
this.parent = parent;
}
public Treap(long x, double y, Treap left = null, Treap right = null)
{
this.x = x;
this.y = y;
this.Left = left;
this.Right = right;
min = x;
Recalc();
}
static void DFS(Treap current, Treap parent)
{
ans[dict[current.x]] = new vertex
{
parent = (parent == null ? 0 : dict[parent.x]),
left = (current.left == null ? 0 : dict[current.left.x]),
right = (current.right == null ? 0 : dict[current.right.x]),
};
if (current.left != null)
{
DFS(current.left, current);
}
if (current.right != null)
{
DFS(current.right, current);
}
}
public static Treap Merge(Treap first, Treap second)
{
if (first == null)
{
return(second);
}
if (second == null)
{
return(first);
}
if (first.y > second.y)
{
return(new Treap(first.x, first.y, first.left, Merge(first.right, second)));
}
else
{
return(new Treap(second.x, second.y, Merge(first, second.left), second.right));
}
}
public static Treap Merge(Treap L, Treap R)
{
if (L == null)
{
return(R);
}
if (R == null)
{
return(L);
}
// TreapnewT;
if (L.y > R.y)
{
return(new Treap(L.x, L.y, L.Left, Merge(L.Right, R)));
}
else
{
return(new Treap(R.x, R.y, Merge(L, R.Left), R.Right));
}
}
public static Treap Build(int[] xs, int[] ys)
{
var tree = new Treap(xs[0], ys[0]);
var last = tree;
for (int i = 1; i < xs.Length; ++i)
{
if (last.y > ys[i])
{
last.right = new Treap(xs[i], ys[i], parent: last);
last = last.right;
}
else
{
Treap cur = last;
while (cur.parent != null && cur.y <= ys[i])
{
cur = cur.parent;
}
if (cur.y <= ys[i])
{
last = new Treap(xs[i], ys[i], cur);
}
else
{
last = new Treap(xs[i], ys[i], cur.right, null, cur);
cur.right = last;
}
}
}
while (last.parent != null)
{
last = last.parent;
}
return(last);
}
