#include using namespace std; // A utility function to search x in arr[] of size n int search(int arr[], int x, int n) { for (int i = 0; i < n; i++) if (arr[i] == x) return i; return -1; } // Prints postorder traversal from given inorder and preorder traversals void printPostOrder(int in[], int pre[], int n) { // The first element in pre[] is always root, search it // in in[] to find left and right subtrees int root = search(in, pre[0], n); // If left subtree is not empty, print left subtree if (root != 0) printPostOrder(in, pre + 1, root); // If right subtree is not empty, print right subtree if (root != n - 1) printPostOrder(in + root + 1, pre + root + 1, n - root - 1); // Print root cout << pre[0] << " "; } // Driver program to test above functions int main() { int in[] = { 4, 2, 5, 1, 3, 6 }; int pre[] = { 1, 2, 4, 5, 3, 6 }; int n = sizeof(in) / sizeof(in[0]); cout << "Postorder traversal " << endl; printPostOrder(in, pre, n); return 0; }

COnvert into three parts, main file cpp file header file