btreemaxsumpathbetween2leaves.c

/* Copyright © 2021-2023 Chee Bin HOH. All rights reserved.
 *
 * Find the maximum sum path between two leaves in a binary tree.
 */

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

int findMaxinumSumPathBetween2Leaves(struct TreeNode *root, int val1,
                                     int val2) {
  int sum1;
  int sum2;

  root = findLeastCommonAncestor(root, val1, val2);
  if (NULL == root)
    return 0;

  sum1 = findMaximumSumPathToLeafValue(root, val1);
  sum2 = findMaximumSumPathToLeafValue(root, val2);

  return sum1 + sum2 - root->val;
}

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 = 3;
  other->left = NULL;
  other->right = NULL;
  root->left->left = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 4;
  other->left = NULL;
  other->right = NULL;
  root->left->right = other;

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

  other = malloc(sizeof(struct TreeNode));
  other->val = 5;
  other->left = NULL;
  other->right = NULL;
  root->right->right = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 6;
  other->left = NULL;
  other->right = NULL;
  root->right->right->left = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 7;
  other->left = NULL;
  other->right = NULL;
  root->right->right->left->right = other;

  other = malloc(sizeof(struct TreeNode));
  other->val = 8;
  other->left = NULL;
  other->right = NULL;
  root->right->right->right = other;

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

  printf("The maximum sum path between leaves %d and %d is %d\n", 3, 4,
         findMaxinumSumPathBetween2Leaves(root, 3, 4));
  printf("The maximum sum path between leaves %d and %d is %d\n", 8, 7,
         findMaxinumSumPathBetween2Leaves(root, 8, 7));
  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;
}