_1161.java

packagecom.fishercoder.solutions.secondthousand;

importcom.fishercoder.common.classes.TreeNode;
importjava.util.LinkedList;
importjava.util.Queue;
importjava.util.TreeMap;

publicclass_1161 {
publicstaticclassSolution1 {
publicintmaxLevelSum(TreeNoderoot) {
if (root == null) {
return0;
 }
Queue<TreeNode> q = newLinkedList<>();
q.offer(root);
TreeMap<Integer, Integer> treeMap = newTreeMap<>((a, b) -> b - a);
intlevel = 1;
while (!q.isEmpty()) {
intsize = q.size();
intsum = 0;
for (inti = 0; i < size; i++) {
TreeNodecurr = q.poll();
sum += curr.val;
if (curr.left != null) {
q.offer(curr.left);
 }
if (curr.right != null) {
q.offer(curr.right);
 }
 }
treeMap.put(sum, level);
level++;
 }
returntreeMap.firstEntry().getValue();
 }
 }
}