54 lines
1.5 KiB
C++
54 lines
1.5 KiB
C++
#include <iostream>
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class TreeNode {
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public:
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int val;
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TreeNode* left;
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TreeNode* right;
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TreeNode(int value) : val(value), left(NULL), right(NULL) {}
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};
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void preorderTraversal(TreeNode* root) {
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TreeNode *current=root;
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TreeNode *rightmost;
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while(current != nullptr){
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if(current->left != nullptr){
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rightmost=current->left;
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while(rightmost->right!=nullptr && rightmost->right!=current){
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rightmost=rightmost->right;
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}
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if(rightmost->right==nullptr){ /* first time */
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std::cout << current->val << " ";
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rightmost->right=current;
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current=current->left;
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}else{ /* second time */
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rightmost->right=nullptr;
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current=current->right;
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}
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}else{ /* nodes which do not have left child */
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std::cout << current->val << " ";
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current=current->right;
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}
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}
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return;
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}
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int main() {
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TreeNode* root = new TreeNode(1);
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root->left = new TreeNode(2);
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root->right = new TreeNode(3);
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root->left->left = new TreeNode(4);
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root->left->right = new TreeNode(5);
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root->left->right->left = new TreeNode(6);
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root->left->right->right = new TreeNode(7);
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root->right->right = new TreeNode(8);
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root->right->right->left = new TreeNode(9);
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std::cout << "Preorder Traversal using Morris Traversal:\n";
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preorderTraversal(root);
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std::cout << std::endl;
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return 0;
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}
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