Max Level Sum in Tree

Max Level Sum in Tree

  December 18, 2017    

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Idea is to use BFS and every time level ends we will add null at end iff there is other nodes in queue

Code:

public static int maxLevelSum(Node root)
         {
         if(root==null)
return 0;
Queue<Node> q=new LinkedList<Node>();
q.add(root);
q.add(null);
int ans=root.data;
int temp=0;
while(!q.isEmpty())
{
Node t=q.poll();
if(t!=null)
{
temp+=t.data;
if(t.left!=null)
q.add(t.left);
  if(t.right!=null)
q.add(t.right);
}
else
{
ans=Math.max(ans,temp);
temp=0;
if(!q.isEmpty())
q.add(null);
}
}
return ans;
          }