Binary Tree Traversals

struct node {  int val;  node *ls, *rs; } 

void preorder(node *rt) {  cout << rt -> val << endl;  preorder(rt -> ls);  preorder(rt -> rs); } 

void inorder(node *rt) {  inorder(rt -> ls);  cout << rt -> val << endl;  inorder(rt -> rs); } 

void postorder(node *rt) {  postorder(rt -> ls);  postorder(rt -> rs);  cout << rt -> val << endl; }