Data Structure Binary Tree: Largest Independent Set Problem

http://www.geeksforgeeks.org/largest-independent-set-problem/

 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 int LISS(node *root) {

19     if (!root) return 0;

20     int sum = 1;

21     if (root->left) sum += LISS(root->left->left) + LISS(root->left->right);

22     if (root->right) sum += LISS(root->right->left) + LISS(root->right->right);

23     return max(sum, LISS(root->left) + LISS(root->right));

24 }

25 

26 int main() {

27     node *root = new node(20);

28     root->left = new node(8);

29     root->right = new node(22);

30     root->left->left = new node(4);

31     root->left->right = new node(12);

32     root->left->right->left = new node(10);

33     root->left->right->right = new node(14);

34     root->right->right = new node(25);

35     cout << LISS(root);

36     return 0;

37 }