dont copy node data in tree delete operation - just swap nodes

This commit is contained in:
IlyaShurupov 2024-04-01 16:51:58 +03:00
parent 6148ff15d2
commit 738ce1d914
3 changed files with 98 additions and 45 deletions

View file

@ -54,7 +54,7 @@ namespace tp {
};
public:
AvlTree() {}
AvlTree() = default;
~AvlTree() { removeAll(); }
[[nodiscard]] ualni size() const { return mSize; }
@ -125,34 +125,53 @@ namespace tp {
}
}
// checks invariants of AVL tree
// returns first invalid node
const Node* findInvalidNode(const Node* head) const {
if (head == nullptr) return nullptr;
if (head->mLeft) {
// TODO: incomplete test
if (head->key.descentRight(head->mLeft->key.getFindKey(head))) return head;
if (head->mLeft->mParent != head) return head;
if (!head->mRight && head->mLeft->mHeight != head->mHeight - 1) return head;
if (head->key.descentRight(head->mLeft->key.getFindKey(head))) {
return head;
}
if (head->mLeft->mParent != head) {
return head;
}
if (!head->mRight && head->mLeft->mHeight != head->mHeight - 1) {
return head;
}
}
if (head->mRight) {
if (!head->key.descentRight(head->mRight->key.getFindKey(head))) return head;
if (head->mRight->mParent != head) return head;
if (!head->mLeft && head->mRight->mHeight != head->mHeight - 1) return head;
if (!head->key.descentRight(head->mRight->key.getFindKey(head))) {
return head;
}
if (head->mRight->mParent != head) {
return head;
}
if (!head->mLeft && head->mRight->mHeight != head->mHeight - 1) {
return head;
}
}
if (head->mLeft && head->mRight) {
if (max(head->mLeft->mHeight, head->mRight->mHeight) != head->mHeight - 1) return head;
if (max(head->mLeft->mHeight, head->mRight->mHeight) != head->mHeight - 1) {
return head;
}
}
int balance = getNodeHeight(head->mRight) - getNodeHeight(head->mLeft);
if (balance > 1 || balance < -1) return head;
if (balance > 1 || balance < -1) {
return head;
}
const Node* ret = findInvalidNode(head->mRight);
if (ret) return ret;
if (ret) {
return ret;
}
return findInvalidNode(head->mLeft);
}
@ -195,20 +214,55 @@ namespace tp {
inline void deleteNode(Node* node) {
node->~Node();
mAlloc.deallocate(node);
mSize--;
}
inline Node* newNode(KeyArg key, DataArg data) { return new (mAlloc.allocate(sizeof(Node))) Node(key, data); }
inline void injectNodeInstead(Node* place, Node* inject) {
// TODO : swap instead of copy
place->data = inject->data;
place->key = inject->key;
// swaps pointers of two nodes to preserve data location in the memory instead of swapping data directly
inline void injectNodeInstead(Node* target, Node* from) {
// 'target' always has two nodes
// 'from' has only one child on the right on no child at all
// 'from' can be right child of the 'target'
// 'target' can or can not have parent
// 'target' can be left or right child of parent
// from is not a child of target
Node* targetParent = target->mParent;
Node* targetLeft = target->mLeft;
Node* targetRight = target->mRight;
bool special = target->mRight == from;
// update parent
if (targetParent) {
if (targetParent->mRight == target) targetParent->mRight = from;
else targetParent->mLeft = from;
}
// clone 'from' to 'target'
target->mParent = special ? from : from->mParent;
target->mLeft = nullptr;
target->mRight = from->mRight;
if (!special) target->mParent->mLeft = target;
// if (target->mLeft) target->mLeft->mParent = target;
if (target->mRight) target->mRight->mParent = target;
// clone 'target' to 'from'
from->mParent = targetParent;
from->mLeft = targetLeft;
from->mRight = special ? target : targetRight;
from->mLeft->mParent = from;
from->mRight->mParent = from;
std::swap(from->mHeight, target->mHeight);
}
inline alni getNodeHeight(const Node* node) const { return node ? node->mHeight : -1; }
// returns new head
Node* rotateLeft(Node* pivot) {
inline Node* rotateLeft(Node* pivot) {
DEBUG_ASSERT(pivot);
Node* const head = pivot;
@ -236,7 +290,7 @@ namespace tp {
return right;
}
Node* rotateRight(Node* pivot) {
inline Node* rotateRight(Node* pivot) {
DEBUG_ASSERT(pivot);
Node* const head = pivot;
@ -318,22 +372,36 @@ namespace tp {
if (head->key.exactNode(key)) {
if (head->mRight && head->mLeft) {
Node* min = minNode(head->mRight);
auto const& newKey = min->key.getFindKey(head->mRight);
injectNodeInstead(head, min);
head->mRight = removeUtil(head->mRight, newKey);
std::swap(head, min);
// auto const& newKey = min->key.getFindKey(head->mRight);
head->mRight = removeUtil(head->mRight, key);
} else if (head->mRight) {
injectNodeInstead(head, head->mRight);
deleteNode(head->mRight);
head->mRight = nullptr;
mSize--;
if (head->mParent) {
if (head->mParent->mLeft == head) head->mParent->mLeft = head->mRight;
else head->mParent->mRight = head->mRight;
}
head->mRight->mParent = head->mParent;
auto delNode = head;
head = head->mRight;
deleteNode(delNode);
} else if (head->mLeft) {
injectNodeInstead(head, head->mLeft);
deleteNode(head->mLeft);
head->mLeft = nullptr;
mSize--;
if (head->mParent) {
if (head->mParent->mLeft == head) head->mParent->mLeft = head->mLeft;
else head->mParent->mRight = head->mLeft;
}
head->mLeft->mParent = head->mParent;
auto delNode = head;
head = head->mLeft;
deleteNode(delNode);
} else {
deleteNode(head);
mSize--;
head = nullptr;
}
} else if (head->key.descentRight(key)) {

View file

@ -1,16 +0,0 @@
#include "Tree.hpp"
#include "Timing.hpp"
#include "UnitTest++/UnitTest++.h"
#include <map>
TEST(AVLTreeStream) {
tp::Timer timer(1000);
tp::AvlTree<tp::AvlNumericKey<tp::ualni>> tree;
while (!timer.isTimeout()) {
tree.
}
}

View file

@ -24,7 +24,7 @@ SUITE(AvlTree) {
TEST(Persistance) {
AvlTree<AvlNumericKey<alni>, TestClass, TestAllocator> tree;
const auto size = 1000;
const auto size = 10;
struct Item {
Item() :
@ -87,6 +87,8 @@ SUITE(AvlTree) {
tree.remove((alni) buff[idx].data.getVal());
CHECK(tree.isValid());
unloadSize++;
buff[idx].presents = false;
@ -120,5 +122,4 @@ SUITE(AvlTree) {
CHECK(tree.maxNode(tree.head()) == nullptr);
CHECK(tree.minNode(tree.head()) == nullptr);
}
}