239. Children Sum Property in Binary Tree

Given the root of a binary tree, return true if and only if every node’s value is equal to the sum of the values stored in its left and right children.

  • For any missing ( null ) child, its value is treated as 0.
  • A leaf node automatically satisfies the rule because both children are null.

Example 1:

Input: root = [1,4,3,5]

Output: false

Explanation:

  • The root is 1, but its children sum to 4 + 3 = 7. Since 1 ≠ 7, the tree violates the property.

Example 2:

Input: root = [10,4,6,1,3,2,4]

Output: true

Explanation:

  • 4 = 1 + 3
  • 6 = 2 + 4
  • 10 = 4 + 6
  • All internal nodes satisfy the condition.

Now Your Turn!

Pick the correct output for the given input

Input: root = [35,20,15,15,5,10,5]

Still unsure what the problem is asking ?

Let’s go through a few more examples, step by step, to make it clearer.

Constraints:

1 ≤ n ≤ 104 (n = number of nodes `)

-105 ≤ Node.val ≤ 105

0
/* class TreeNode {
int val;
TreeNode *left, *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
*/
 
class Solution {
public:
bool checkChildrenSum(TreeNode* root) {
// Your code goes here
}
};
 
Test Case

Input:

Root
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