DS

Treap ATTENTION: 出门左转 https://caterpillow.github.io/byot 谢谢喵 又名笛卡尔树，随机BST；支持$log n$插入，删除，查找及闭包操作(push_up) https://cp-algorithms.com/data_structures/treap.html https://oi.baoshuo.ren/fhq-treap A. std::set 类容器 template<typename T> struct treap { struct node { T key; ll priority; ll l, r; // push_up maintains ll size; }; vector<node> tree; vec free_list; private: void push_up(ll o) { tree[o].size = tree[tree[o].l].size + tree[tree[o].r].size + 1; } II split_by_value(ll o, T const& key) { // 偏序 [<, >=] if (!o) return {0,0}; if (tree[o].key < key) { // 左大右小 auto [ll,rr] = split_by_value(tree[o]....