# Get First node at a given level in a BT

Can you please help with C code to get first node in a binary tree given a particular level .

I have made small changes for printing first node, in level order traversal code sourced from here :

http://www.geeksforgeeks.org/level-order-tree-traversal/

and now it prints first node of specified level :

```// Recursive C program for level order traversal of Binary Tree
#include <stdio.h>
#include <stdlib.h>

/* A binary tree node has data, pointer to left child
and a pointer to right child */
struct node
{
int data;
struct node* left, *right;
};

/* Function protoypes */
void printGivenLevel(struct node* root, int level);
int height(struct node* node);
struct node* newNode(int data);
int firstNode;

/* Function to print level order traversal a tree*/
void printLevelOrder(struct node* root)
{
int h = height(root);
int i;
for (i=1; i<=h; i++)
printGivenLevel(root, i);
}

/* Print nodes at a given level */
void printGivenLevel(struct node* root, int level)
{
if (root == NULL)
return;
if (level == 1)
{
//	Just store first node,    it will be -1 if not assigned yet
if (firstNode == -1)
firstNode = root->data;
}
else if (level > 1)
{
printGivenLevel(root->left, level-1);
printGivenLevel(root->right, level-1);
}
}

/* Compute the "height" of a tree -- the number of
nodes along the longest path from the root node
down to the farthest leaf node.*/
int height(struct node* node)
{
if (node==NULL)
return 0;
else
{
/* compute the height of each subtree */
int lheight = height(node->left);
int rheight = height(node->right);

/* use the larger one */
if (lheight > rheight)
return(lheight+1);
else return(rheight+1);
}
}

/* Helper function that allocates a new node with the
given data and NULL left and right pointers. */
struct node* newNode(int data)
{
struct node* node = (struct node*)malloc(sizeof(struct node));
node->data = data;
node->left = NULL;
node->right = NULL;

return(node);
}

/* Driver program to test above functions*/
int main()
{
struct node *root = newNode(1);
root->left        = newNode(2);
root->right       = newNode(3);
root->left->left  = newNode(4);
root->left->right = newNode(5);

printf("Level Order traversal of binary tree is \n");
firstNode = -1;
printGivenLevel(root, 2);
printf("%d\n", firstNode);

return 0;
}```