Hello! So I’m doing a 30 day coding challenge where I solve a few questions every day and thought of posting them here on my blog so that you guys can join the challenge too!
Welcome to Coding challenge Day 14: Problem 1! Be sure to post your answers, queries etc in the comments!
Problem: Find the level that has maximum number sum in the Binary tree
Sample:

Output: Max sum at level 2 having sum= 22
Solution:
Note that the following exercise is in JAVA
package tree.binarytree;
import java.util.Queue;
import java.util.LinkedList;
public class Program012max_sum_level {
static class Node {
int data;
Node left, right;
public Node (int d){
data= d;
left=right=null;
}
}
static class Binary_tree{
Node root;
public Binary_tree (){
root= null;
}
public void add_left (Node parent_node, Node node){
parent_node.left= node;
}
public void add_right (Node parent_node, Node node){
parent_node.right= node;
}
public void max_sum (){
Node node= root;
Node level_order= new Node(-1);
Node previous_node= root;
int level=0;
Queue<Node> queue= new LinkedList<Node>();
int sum=0, max_sum=0, max_level=0;
queue.add(root);
queue.add(level_order);
while(!queue.isEmpty()){
Node front_node= queue.poll();
if(front_node.data==-1){
if(sum>max_sum){
max_sum=sum;
max_level=level;
}
level++;
sum=0;
if(previous_node.data!=-1){
queue.add(level_order);
}
}else {
sum+=front_node.data;
if(front_node.left!=null)
queue.add(front_node.left);
if (front_node.right!=null)
queue.add(front_node.right);
}
previous_node= front_node;
}
System.out.println("Max sum at level " + max_level + " having sum= " + max_sum);
}
}
public static void main (String [] args){
Binary_tree tree= new Binary_tree();
tree.root= new Node(1);
Node node2= new Node(2);
tree.add_left(tree.root, node2);
Node node3= new Node(3);
tree.add_right(tree.root, node3);
Node node4= new Node (4);
tree.add_left(node2, node4);
Node node5= new Node(5);
tree.add_right(node2, node5);
Node node6= new Node(6);
tree.add_left(node3, node6);
Node node7= new Node(7);
tree.add_right(node3, node7);
tree.max_sum();
}
}
Happy Learning!!