diff options
Diffstat (limited to 'datastructures/treap.cpp')
| -rw-r--r-- | datastructures/treap.cpp | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/datastructures/treap.cpp b/datastructures/treap.cpp deleted file mode 100644 index c96e36a..0000000 --- a/datastructures/treap.cpp +++ /dev/null @@ -1,79 +0,0 @@ -struct node { - int key, prio, left, right, size; - node(int key, int prio) : key(key), prio(prio), left(-1), - right(-1), size(1) {}; -}; - -vector<node> treap; - -int getSize(int root) { - return root < 0 ? 0 : treap[root].size; -} - -void update(int root) { - if (root < 0) return; - treap[root].size = 1 + getSize(treap[root].left) - + getSize(treap[root].right); -} - -pair<int, int> split(int root, int minKeyRight) { - if (root < 0) return {-1, -1}; - if (treap[root].key >= minKeyRight) { - auto leftSplit = split(treap[root].left, minKeyRight); - treap[root].left = leftSplit.second; - update(root); - leftSplit.second = root; - return leftSplit; - } else { - auto rightSplit = split(treap[root].right, minKeyRight); - treap[root].right = rightSplit.first; - update(root); - rightSplit.first = root; - return rightSplit; -}} - -int merge (int left, int right) { - if (left < 0) return right; - if (right < 0) return left; - if (treap[left].prio < treap[right].prio) { //min priority heap - treap[left].right = merge(treap[left].right, right); - update(left); - return left; - } else { - treap[right].left = merge(left, treap[right].left); - update(right); - return right; -}} - -//insert values with high priority first -int insert(int root, int key, int prio) { - int next = sz(treap); - treap.emplace_back(key, prio); - auto t = split(root, key); - //returns new root - return merge(merge(t.first, next), t.second); -} - -int remove(int root, int key) { - if (root < 0) return -1; - if (key < treap[root].key) { - treap[root].left = remove(treap[root].left, key); - update(root); - return root; - } else if (key > treap[root].key) { - treap[root].right = remove(treap[root].right, key); - update(root); - return root; - } else { //check prio? - return merge(treap[root].left, treap[root].right); -}} - -int kth(int root, int k) { - if (root < 0) return -1; - int leftSize = getSize(treap[root].left); - if (k < leftSize) return kth(treap[root].left, k); - else if (k > leftSize) { - return kth(treap[root].right, k - 1 - leftSize); - } - return root; -} |
