红黑树是一种自平衡的二叉搜索树,其基本结构可以通过以下代码实现:
#include <iostream>
using namespace std;
enum Color {RED, BLACK};
struct Node {
int data;
Color color;
Node* left;
Node* right;
Node* parent;
Node(int val) : data(val), color(RED), left(nullptr), right(nullptr), parent(nullptr) {}
};
class RedBlackTree {
private:
Node* root;
void leftRotate(Node* x) {
Node* y = x->right;
x->right = y->left;
if (y->left != nullptr) {
y->left->parent = x;
}
y->parent = x->parent;
if (x->parent == nullptr) {
root = y;
} else if (x == x->parent->left) {
x->parent->left = y;
} else {
x->parent->right = y;
}
y->left = x;
x->parent = y;
}
void rightRotate(Node* y) {
Node* x = y->left;
y->left = x->right;
if (x->right != nullptr) {
x->right->parent = y;
}
x->parent = y->parent;
if (y->parent == nullptr) {
root = x;
} else if (y == y->parent->left) {
y->parent->left = x;
} else {
y->parent->right = x;
}
x->right = y;
y->parent = x;
}
void fixViolation(Node* z) {
while (z != root && z->parent->color == RED) {
if (z->parent == z->parent->parent->left) {
Node* y = z->parent->parent->right;
if (y != nullptr && y->color == RED) {
z->parent->color = BLACK;
y->color = BLACK;
z->parent->parent->color = RED;
z = z->parent->parent;
} else {
if (z == z->parent->right) {
z = z->parent;
leftRotate(z);
}
z->parent->color = BLACK;
z->parent->parent->color = RED;
rightRotate(z->parent->parent);
}
} else {
Node* y = z->parent->parent->left;
if (y != nullptr && y->color == RED) {
z->parent->color = BLACK;
y->color = BLACK;
z->parent->parent->color = RED;
z = z->parent->parent;
} else {
if (z == z->parent->left) {
z = z->parent;
rightRotate(z);
}
z->parent->color = BLACK;
z->parent->parent->color = RED;
leftRotate(z->parent->parent);
}
}
}
root->color = BLACK;
}
public:
RedBlackTree() : root(nullptr) {}
void insert(int val) {
Node* z = new Node(val);
Node* y = nullptr;
Node* x = root;
while (x != nullptr) {
y = x;
if (z->data < x->data) {
x = x->left;
} else {
x = x->right;
}
}
z->parent = y;
if (y == nullptr) {
root = z;
} else if (z->data < y->data) {
y->left = z;
} else {
y->right = z;
}
fixViolation(z);
}
// Traversal functions (inorder, preorder, postorder)
// Other functions like delete, search, etc. can also be added
};
int main() {
RedBlackTree rbTree;
rbTree.insert(7);
rbTree.insert(3);
rbTree.insert(18);
rbTree.insert(10);
rbTree.insert(22);
return 0;
}
在上面的代码中,我们定义了一个Node
结构体表示红黑树的节点,其中包含数据值、颜色、左右孩子节点以及父节点。然后定义了一个RedBlackTree
类来实现红黑树的基本操作,包括左旋转、右旋转、修正插入操作中可能出现的违反规则的情况等。
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