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  1. #include <iostream>
  2. #include <utility>
  3. #include <algorithm>
  4. #include <list>
  5.  
  6. namespace tree {
  7.  
  8. template<typename T>
  9. struct node
  10. {
  11. T data;
  12. node* l;
  13. node* r;
  14. node(T&& data_ = T()) : data(std::move(data_)), l(0), r(0) {}
  15. };
  16.  
  17. template<typename T>
  18. int max_depth(node<T>* n)
  19. {
  20. if (!n) return 0;
  21. return 1 + std::max(max_depth(n->l), max_depth(n->r));
  22. }
  23.  
  24. template<typename T>
  25. void prt(node<T>* n)
  26. {
  27. struct node_depth
  28. {
  29. node<T>* n;
  30. int lvl;
  31. node_depth(node<T>* n_, int lvl_) : n(n_), lvl(lvl_) {}
  32. };
  33.  
  34. int depth = max_depth(n);
  35.  
  36. char buf[1024];
  37. int last_lvl = 0;
  38. int offset = (1 << depth) - 1;
  39.  
  40. // using a queue means we perform a breadth first iteration through the tree
  41. std::list<node_depth> q;
  42.  
  43. q.push_back(node_depth(n, last_lvl));
  44. while (q.size())
  45. {
  46. const node_depth& nd = *q.begin();
  47.  
  48. // moving to a new level in the tree, output a new line and calculate new offset
  49. if (last_lvl != nd.lvl)
  50. {
  51. std::cout << "\n";
  52.  
  53. last_lvl = nd.lvl;
  54. offset = (1 << (depth - nd.lvl)) - 1;
  55. }
  56.  
  57. // output <offset><data><offset>
  58. if (nd.n)
  59. sprintf(buf, " %*s%d%*s", offset, " ", nd.n->data, offset, " ");
  60. else
  61. sprintf(buf, " %*s", offset << 1, " ");
  62. std::cout << buf;
  63.  
  64. if (nd.n)
  65. {
  66. q.push_back(node_depth(nd.n->l, last_lvl + 1));
  67. q.push_back(node_depth(nd.n->r, last_lvl + 1));
  68. }
  69.  
  70. q.pop_front();
  71. }
  72. std::cout << "\n";
  73. }
  74.  
  75. }
  76.  
  77. int main()
  78. {
  79. typedef tree::node<int> node;
  80. node* head = new node();
  81. head->l = new node(1);
  82. head->r = new node(2);
  83. head->l->l = new node(3);
  84. head->l->r = new node(4);
  85. head->r->l = new node(5);
  86. head->r->r = new node(6);
  87.  
  88. tree::prt(head);
  89.  
  90. return 0;
  91. }
Success #stdin #stdout 0s 3060KB
stdin
Standard input is empty
stdout
        0       
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  3   4   5   6