http://www.geeksforgeeks.org/morris-traversal-for-preorder/
1 #include <iostream> 2 #include <vector> 3 #include <algorithm> 4 #include <queue> 5 #include <stack> 6 #include < string > 7 #include <fstream> 8 #include <map> 9 using namespace std; 10 11 struct node { 12 int data; 13 struct node *left, * right; 14 node() : data( 0 ), left(NULL), right(NULL) { } 15 node( int d) : data(d), left(NULL), right(NULL) { } 16 }; 17 18 void prints(node * root) { 19 while (root) { 20 if (root->left == NULL) { 21 cout << root->data << " " ; 22 root = root-> right; 23 } 24 else { 25 node* cur = root-> left; 26 while (cur->right && cur->right != root) cur = cur-> right; 27 if (cur->right == NULL) { 28 cout << root->data << " " ; 29 cur->right = root; 30 root = root-> left; 31 } 32 else { 33 cur->right = NULL; 34 root = root-> right; 35 } 36 } 37 } 38 } 39 40 int main() { 41 node *root = new node( 1 ); 42 root->left = new node( 2 ); 43 root->right = new node( 3 ); 44 root->left->left = new node( 4 ); 45 root->left->right = new node( 5 ); 46 root->right->left = new node( 6 ); 47 root->right->right = new node( 7 ); 48 root->left->left->left = new node( 8 ); 49 root->left->left->right = new node( 9 ); 50 root->left->right->left = new node( 10 ); 51 root->left->right->right = new node( 11 ); 52 prints(root); 53 return 0 ; 54 }