btreesymmetriccheck.c

/* Copyright © 2021-2023 Chee Bin HOH. All rights reserved.
 *
 * Check if tree is symmetric that right branch of root is mirror of left branch
 * in layout of the tree (not the values of node).
 */

#include "btree.h"
#include <stdio.h>
#include <stdlib.h>

void checkIfTreeIsSysmetric(struct TreeNode *root) {
  if (isTreeSymmetric(root)) {
    printf("The tree is symmetric\n");
  } else {
    printf("The tree is not symmetric\n");
  }
}

int main(int argc, char *argv[]) {
  struct TreeNode *root = NULL;
  struct TreeNode *other = NULL;

  root = malloc(sizeof(struct TreeNode));
  root->val = 0;
  root->left = NULL;
  root->right = NULL;

  other = malloc(sizeof(struct TreeNode));
  other->val = 1;
  other->left = NULL;
  other->right = NULL;
  root->left = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 1;
  other->left = NULL;
  other->right = NULL;
  root->right = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 2;
  other->left = NULL;
  other->right = NULL;

  root->right->right = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 2;
  other->left = NULL;
  other->right = NULL;

  root->left->left = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 3;
  other->left = NULL;
  other->right = NULL;

  root->left->right = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 3;
  other->left = NULL;
  other->right = NULL;

  root->right->left = other;

  printf("The tree topology:\n");
  printf("\n");
  printTreeNodeInTreeTopology(root);
  printf("\n");

  checkIfTreeIsSysmetric(root);
  printf("\n");
  printf("\n");

  root->right->left = NULL;

  printf("The tree topology (after setting root->right->left to NULL):\n");
  printf("\n");
  printTreeNodeInTreeTopology(root);
  printf("\n");

  checkIfTreeIsSysmetric(root);
  printf("\n");
  printf("\n");

  // I do not care about freeing malloced memory, OS will take care of freeing
  // heap that is part of process for this one off program.

  return 0;
}