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  1. #include <bits/stdc++.h>
  2.  
  3. using namespace std;
  4.  
  5. struct node
  6. {
  7.     int data;
  8.     struct node *left;
  9.     struct node *right;
  10. };
  11.  
  12. struct node* add(int x)
  13. {
  14.      struct node *temp = ( struct node *) malloc(sizeof(struct node));
  15.      temp->data = x;
  16.      temp->left = NULL;
  17.      temp->right = NULL;
  18.      return temp;
  19.  
  20. };
  21.  
  22. void leave( struct node *root )
  23. {
  24.  
  25.     if ( root != NULL ) {
  26.  
  27.          if ( root->left == NULL && root->right == NULL  ){
  28.             cout << root->data << " ";
  29.          }
  30.          leave(root->left);
  31.          leave(root->right);
  32.     }
  33.  
  34. }
  35. void boundary_l( struct node *root)
  36. {
  37.     if ( root != NULL ) {
  38.  
  39.         if ( root->left == NULL && root->right == NULL ) {
  40.             return;
  41.         }
  42.         cout << root->data <<"  ";
  43.         boundary_l(root->left);
  44.         boundary_l(root->right);
  45.  
  46.     }
  47.     return;
  48. }
  49. void boundary_r(struct node *root)
  50. {
  51.     if ( root != NULL ) {
  52.  
  53.         if ( root->left == NULL && root->right == NULL ) {
  54.             return;
  55.         }
  56.  
  57.         boundary_l(root->right);
  58.         boundary_l(root->left);
  59.         cout << root->data <<"  ";
  60.     }
  61.     return;
  62.  
  63. }
  64.  
  65. void boundary( struct node *root)
  66. {
  67.  
  68.     if ( root != NULL ) {
  69.         cout << root->data << " ";
  70.         boundary_l(root->left);
  71.         leave(root->left);
  72.         leave(root->right);
  73.         boundary_r(root->right);
  74.     }
  75.  
  76. }
  77.  
  78. int main()
  79. {
  80.  
  81.      struct node *root = NULL;
  82.  
  83.      root = add(1);
  84.      root->left = add(2);
  85.      root->right = add(3);
  86.      root->left->left = add(4);
  87.      root->left->right = add(5);
  88.      root->right->left = add(6);
  89.      root->right->right = add(7);
  90.  
  91.     boundary(root);
  92.     return 0;
  93. }
  94.  
Success #stdin #stdout 0s 3428KB
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https://ideone.com/PeuAuF
language:
C++ (gcc 8.3)
created:
9 years ago
visibility:
public

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