public void Split(bool implicitIndex, int key, T value, out Treap <T> left, out Treap <T> right)
{
Root.Split(implicitIndex, key, value, out Node <T> tempLeft, out Node <T> tempRight);
// return two new Treaps to show the trees we now have by updating the root to reflect the
// nodes that were passed back in the call to Split
if (tempLeft != null)
{
left = new Treap <T>()
{
Root = tempLeft
};
}
else
{
left = null;
}
if (tempRight != null)
{
right = new Treap <T>()
{
Root = tempRight
};
}
else
{
right = null;
}
}
static void Main(string[] args)
{
Random rand = new Random();
List <Point> list = new List <Point>();
list.Add(new Point(0, 3));
list.Add(new Point(2, 4));
list.Add(new Point(3, 3));
list.Add(new Point(4, 6));
list.Add(new Point(5, 1));
list.Add(new Point(6, 2));
list.Add(new Point(7, 10));
Treap tree = new Treap(list);
tree.Print(tree.root);
}
static void Main(string[] args)
{
string[] nm = Console.ReadLine().Split(' ');
int n = Convert.ToInt32(nm[0]);
int m = Convert.ToInt32(nm[1]);
int[] values = Array.ConvertAll(Console.ReadLine().Split(' '), temp => Convert.ToInt32(temp));
int[][] queries = new int[m][];
for (int index = 0; index < m; index++)
{
queries[index] = Array.ConvertAll(Console.ReadLine().Split(' '), temp => Convert.ToInt32(temp));
}
Treap <int> tree = new Treap <int>();
// place all items in the treap, adding each one as we go. Because our treap has implicit indexing
// all items will be inserted as such that we can do an in order traversal and get the array back
// in 0 to N-1 order where N is the length of the array
for (int index = 0; index < values.Length; index++)
{
// insert with the key being the position, so that an in order traversal will result in the
// array in the order it was entered in
tree[index] = values[index];
}
for (int index = 0; index < m; index++)
{
// we use zero based indexing, so subtract one from whatever is provided
int query = queries[index][0];
int start = queries[index][1] - 1;
int end = queries[index][2] - 1;
// split the root into begin and end trees, storing the end tree into
// a temporary Treap as we are going to split that again
// split based upon the implicit index, which in this case is start - 1 as we are
// using zero based indexing, and need to split on the node before the start value.
// Consider the following example:
// List = { 1, 2, 3, 4, 5, 6, 7, 8 }
// If we want the values 2, 3, and 4 from the list then we would split on the first
// node, giving us:
// beginTree = { 1 }
// tempTree = { 2, 3, 4, 5, 6, 7, 8 }
tree.Split(true, start - 1, 0, out Treap <int> beginTree, out Treap <int> tempTree);
// split based upon the implicit index, but also account for the fact that the tree we are doing a
// split against is smaller given the nodes we took away at the front. The remaining tree is either
// the size of the beginTree, or taking the end value, subtracting the start value (accounting for
// zero based indexes), and that new index being the proper place in the smaller tree to split on.
// Again consider the following example:
// List = { 1, 2, 3, 4, 5, 6, 7, 8 }
// We want the values 2, 3, and 4 from the list, so the start value would be two, and the end value
// would be four. We already did a split on 1, which gave us the following:
// leftTree = { 1 }
// tempTree = { 2, 3, 4, 5, 6, 7, 8 }
// We now need to calculate a different end value, which in this case is end minus start, or
// 4 - 1, meaning we split on position three in the list, giving us:
// middleTree = { 2, 3, 4 }
// endTree = { 5, 6, 7, 8 }
// At this point we can combine our trees in whatever order specified (front or back)
tempTree.Split(true, end - start, 0, out Treap <int> middleTree, out Treap <int> endTree);
// do the following based upon the query type
// type 1: middle + begin + end
// type 2: begin + end + middle
if (query == 1)
{
tree.Merge(beginTree, endTree);
tree.Merge(middleTree, tree);
}
else if (query == 2)
{
tree.Merge(beginTree, endTree);
tree.Merge(tree, middleTree);
}
}
// print the absolute value of the first minus the last element (if the tree
// is empty this will fail, but all test input provided assumes a list of at
// least length one)
Console.WriteLine(Math.Abs(tree.GetFirst().Value - tree.GetLast().Value));
List <int> arr = new List <int>();
// print the present order of the list (an in-order traversal will give the current
// positioning of all elements after merge and split operations)
tree.InOrder(tree.Root, (value) => { arr.Add(value); });
Console.WriteLine(string.Join(" ", arr));
}
public void Merge(Treap <T> left, Treap <T> right)
{
// update the root to reflect the merged tree
// account for the fact the left or right tree could be null
Root = Node <T> .Merge(left?.Root, right?.Root);
}
