1 files changed, 78 insertions, 0 deletions
diff --git a/datastructures/treap2.cpp b/datastructures/treap2.cpp
new file mode 100644
index 0000000..e0c32a6
--- /dev/null
+++ b/datastructures/treap2.cpp
@@ -0,0 +1,78 @@
+mt19937 rng(0xc4bd5dad);
+struct Treap {
+	struct Node {
+		ll val;
+		int prio, sz = 1, l = -1, r = -1;
+		Node (ll x) : val(x), prio(rng()) {}
+	};
+
+	vector<Node> treap;
+	int root = -1;
+
+	int getSize(int v) {
+		return v < 0 ? 0 : treap[v].sz;
+	}
+
+	void upd(int v) {
+		if (v < 0) return;
+		auto *V = &treap[v];
+		V->sz = 1 + getSize(V->l) + getSize(V->r);
+		// Update Node Code
+	}
+
+	void push(int v) {
+		if (v < 0) return;
+		//auto *V = &treap[v];
+		//if (V->lazy) {
+		//	Lazy Propagation Code
+		//	if (V->l >= 0) treap[V->l].lazy = true;
+		//	if (V->r >= 0) treap[V->r].lazy = true;
+		//	V->lazy = false;
+		//}
+	}
+
+	pair<int, int> split(int v, int k) {
+		if (v < 0) return {-1, -1};
+		auto *V = &treap[v];
+		push(v);
+		if (getSize(V->l) >= k) { // "V->val >= k" for lower_bound(k)
+			auto [left, right] = split(V->l, k);
+			V->l = right;
+			upd(v);
+			return {left, v};
+		} else {
+			auto [left, right] = split(V->r, k - getSize(V->l) - 1); // and only "k"
+			V->r = left;
+			upd(v);
+			return {v, right};
+	}}
+
+	int merge(int left, int right) {
+		if (left < 0) return right;
+		if (right < 0) return left;
+		if (treap[left].prio < treap[right].prio) {
+			push(left);
+			treap[left].r = merge(treap[left].r, right);
+			upd(left);
+			return left;
+		} else {
+			push(right);
+			treap[right].l = merge(left, treap[right].l);
+			upd(right);
+			return right;
+	}}
+
+	void insert(int i, ll val) { // and i = val
+		auto [left, right] = split(root, i);
+		treap.emplace_back(val);
+		left = merge(left, sz(treap) - 1);
+		root = merge(left, right);
+	}
+
+	void remove(int i, int count = 1) {
+		auto [left, t_right] = split(root, i);
+		auto [middle, right] = split(t_right, count);
+		root = merge(left, right);
+	}
+	// for query use remove and read middle BEFORE remerging
+};