# Sum of all the grandchild nodes of binary tree in c

C program for Sum of all the grandchild nodes of binary tree. Here more solutions.

``````// Include header file
#include <stdio.h>
#include <stdlib.h>
/*
C program for
Sum of nodes in binary tree whose grandparents exists
*/
// Binary Tree node
typedef struct TreeNode
{
// Define useful field of TreeNode
int data;
struct TreeNode * left;
struct TreeNode * right;
}TreeNode;

TreeNode * getTreeNode(int data)
{
// Create dynamic memory of TreeNode
TreeNode * ref = (TreeNode * ) malloc(sizeof(TreeNode));
if (ref == NULL)
{
// Failed to create memory
return NULL;
}
// Set node value
ref->data = data;
ref->left = NULL;
ref->right = NULL;
return ref;
}
typedef struct BinaryTree
{
// Define useful field of BinaryTree
struct TreeNode * root;
}BinaryTree;

BinaryTree * getBinaryTree()
{
// Create dynamic memory of BinaryTree
BinaryTree * ref = (BinaryTree * ) malloc(sizeof(BinaryTree));
if (ref == NULL)
{
// Failed to create memory
return NULL;
}
// Set initial tree root
ref->root = NULL;
return ref;
}

void preOrder(TreeNode * node)
{
if (node != NULL)
{
// Print node value
printf("  %d", node->data);
// Visit left subtree
preOrder(node->left);
// Visit right subtree
preOrder(node->right);
}
}
int grandchildSum(TreeNode * node, int level)
{
if (node != NULL)
{
int result = 0;
if (level > 2)
{
// Get the node
result = node->data;
}
// Visit left subtree and right subtree
return result +
grandchildSum(node->left, level + 1) +
grandchildSum(node->right, level + 1);
}
else
{
return 0;
}
}
int main()
{
// Create new binary trees
BinaryTree * tree = getBinaryTree();
/*
4
/  \
/    \
12     7
/ \      \
2   3      1
/ \    /
6   8  5
/
9
----------------
Constructing binary tree
*/
tree->root = getTreeNode(4);
tree->root->left = getTreeNode(12);
tree->root->left->right = getTreeNode(3);
tree->root->left->right->left = getTreeNode(6);
tree->root->left->right->left->left = getTreeNode(9);
tree->root->left->right->right = getTreeNode(8);
tree->root->left->left = getTreeNode(2);
tree->root->right = getTreeNode(7);
tree->root->right->right = getTreeNode(1);
tree->root->right->right->left = getTreeNode(5);
// Display tree node
printf("\n Tree Nodes ");
preOrder(tree->root);
// Find node sum
// 2 + 3 + 6 + 9 + 8 + 1 + 5 = 34
int result = grandchildSum(tree->root, 1);
// Display result
printf("\n Result : %d", result);
}``````

Output

`````` Tree Nodes   4  12  2  3  6  9  8  7  1  5
Result : 34``````

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