Data Structure Binary Tree: Convert an arbitrary Binary Tree to a tree that holds Children Sum Property

http://www.geeksforgeeks.org/convert-an-arbitrary-binary-tree-to-a-tree-that-holds-children-sum-property/

 1 #include <iostream>

 2 #include <vector>

 3 #include <algorithm>

 4 #include <queue>

 5 #include <stack>

 6 using namespace std;

 7 

 8 struct node {

 9     int data;

10     struct node *left, *right;

11     node() : data(0), left(NULL), right(NULL) { }

12     node(int d) : data(d), left(NULL), right(NULL) { }

13 };

14 

15 void print(node *node) {

16     if (!node) return;

17     print(node->left);

18     cout << node->data << " ";

19     print(node->right);

20 }

21 

22 void _convert(node* root, int diff) {

23     if (!root) return;

24     if (root->left) {

25         root->left->data += diff;

26         _convert(root->left, diff);

27     }

28     else if (root->right) {

29         root->right->data += diff;

30         _convert(root->right, diff);

31     }

32 }

33 

34 void convert(node* root) {

35     if (!root || !root->left && !root->right) return;

36     convert(root->left);

37     convert(root->right);

38     int sum = 0;

39     sum += root->left? root->left->data : 0;

40     sum += root->right? root->right->data : 0;

41     if (sum >= root->data) root->data = sum;

42     else _convert(root, root->data - sum);

43 }

44 

45 

46 int main() {

47     struct node* root = new node(50);

48     root->left = new node(7);

49     root->right = new node(2);

50     root->left->left = new node(3);

51     root->left->right = new node(5);

52     root->right->left = new node(1);

53     root->right->right = new node(30);

54     print(root);

55     cout << endl;

56     convert(root);

57     print(root);

58     return 0;

59 }