Complete the postOrder function in your editor below, which has parameter: a pointer to the root of a binary tree. It must print the values in the tree's preorder traversal as a single line of space-separated values.

/* you only have to complete the function given below.

Node is defined as

class Node {

public:

int data;

Node *left;

Node *right;

Node(int d) {

data = d;

left = NULL;

right = NULL;

}

};

*/

void postOrder(Node *root) {

}