124 lines
2.2 KiB
C++
124 lines
2.2 KiB
C++
#include <iostream>
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using namespace std;
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struct Node {
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int key;
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Node *left;
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Node *right;
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int height;
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};
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Node *newNode(int key) {
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Node *node = new Node();
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node->key = key;
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node->left = NULL;
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node->right = NULL;
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node->height = 1;
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return (node);
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}
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int height(Node *N) {
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if (N == NULL)
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return 0;
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return N->height;
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}
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int max(int a, int b) {
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return (a > b) ? a : b;
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}
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Node *rightRotate(Node *y) {
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Node *x = y->left;
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Node *T2 = x->right;
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x->right = y;
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y->left = T2;
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y->height = max(height(y->left), height(y->right)) + 1;
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x->height = max(height(x->left), height(x->right)) + 1;
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return x;
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}
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Node *leftRotate(Node *x) {
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Node *y = x->right;
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Node *T2 = y->left;
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y->left = x;
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x->right = T2;
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x->height = max(height(x->left), height(x->right)) + 1;
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y->height = max(height(y->left), height(y->right)) + 1;
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return y;
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}
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int getBalance(Node *N) {
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if (N == NULL)
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return 0;
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return height(N->left) - height(N->right);
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}
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Node *insert(Node *node, int key) {
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if (node == NULL)
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return (newNode(key));
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if (key < node->key)
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node->left = insert(node->left, key);
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else if (key > node->key)
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node->right = insert(node->right, key);
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else
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return node;
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node->height = 1 + max(height(node->left), height(node->right));
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int balance = getBalance(node);
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if (balance > 1 && key < node->left->key)
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return rightRotate(node);
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if (balance < -1 && key > node->right->key)
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return leftRotate(node);
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if (balance > 1 && key > node->left->key) {
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node->left = leftRotate(node->left);
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return rightRotate(node);
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}
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if (balance < -1 && key < node->right->key) {
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node->right = rightRotate(node->right);
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return leftRotate(node);
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}
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return node;
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}
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void preOrder(Node *root) {
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if (root != NULL) {
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cout << root->key << " ";
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preOrder(root->left);
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preOrder(root->right);
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}
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}
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bool isBalanced(Node *root) {
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int balance = getBalance(root);
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if (balance > 1 || balance < -1)
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return false;
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else
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return true;
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}
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int main() {
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Node *root = NULL;
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while (true) {
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int val;
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cin >> val;
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if (val == -1)
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break;
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root = insert(root, val);
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}
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if (isBalanced(root))
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cout << "The tree is balanced.\n";
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else
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cout << "The tree is not balanced.\n";
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cout << "Preorder traversal of the constructed AVL tree is \n";
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preOrder(root);
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return 0;
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}
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