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 }