Update 0662-maximum-width-of-binary-tree.java

java/0662-maximum-width-of-binary-tree.java

@@ -1,21 +1,36 @@
 class Solution {
-
  public int widthOfBinaryTree(TreeNode root) {
- Queue<Pair<TreeNode, Integer>> q = new LinkedList<>();
- int maxWidth = 0;
- q.offer(new Pair(root, 1));
- while (!q.isEmpty()) {
- int l = q.peek().getValue();
- int r = l;
- int size = q.size();
- for (int i = 0; i < size; i++) {
- TreeNode cur = q.peek().getKey();
- r = q.poll().getValue();
- if (cur.left != null) q.offer(new Pair(cur.left, 2 * r));
- if (cur.right != null) q.offer(new Pair(cur.right, 2 * r + 1));
+ int res = 0;
+ Queue<tuple> q = new LinkedList<>();
+ q.add(new tuple(root, 1, 0));
+ int prevLevel = 0, prevNum = 1;
+
+ while(!q.isEmpty()){
+ tuple curr = q.poll();
+ TreeNode node = curr.node;
+ int num = curr.num, level = curr.level;
+
+ if(level > prevLevel){
+ prevLevel = level;
+ prevNum = num;
  }
- maxWidth = Math.max(maxWidth, r - l + 1);
+ res = Math.max(res, num - prevNum + 1);
+ if(node.left != null)
+ q.add(new tuple(node.left, num*2, level + 1));
+ if(node.right != null)
+ q.add(new tuple(node.right, num*2 + 1, level + 1)); 
  }
- return maxWidth;
+ return res;
+ }
+}
+class tuple{
+ TreeNode node;
+ int num;
+ int level;
+
+ public tuple(TreeNode node, int num, int level){
+ this.node = node;
+ this.num = num;
+ this.level = level;
  }
 }