515. Find Largest Value in Each Tree Row

仍然是BFS的变式。

class Solution {
    public List largestValues(TreeNode root) {
        List result = new ArrayList<>();
        ArrayDeque queue = new ArrayDeque<>();
        if(root==null)return result;
        queue.add(root);
        while(!queue.isEmpty())
        {
            int size = queue.size();
            int max=Integer.MIN_VALUE;
            for(int i = 0 ;imax)
                    max=node.val;
                if(node.left!=null)
                    queue.add(node.left);
                if(node.right!=null)
                    queue.add(node.right);
            }
            result.add(max);
        }
        return result ;
        
    }
}