#104.Maximum Depth of Binary Tree [LeetCode Grind 75 in Java]
[Problem Link] https://leetcode.com/problems/maximum-depth-of-binary-tree/
class Solution {
public int maxDepth(TreeNode root) {
if(root == null) return 0;
//BFS traversal
Queue<TreeNode> q = new LinkedList<TreeNode>();
q.add(root);
int depth = 0;
while(!q.isEmpty()){
int sz = q.size();
depth ++;
while(sz -- > 0){
TreeNode curr = q.poll();
if(curr.left != null) q.add(curr.left);
if(curr.right != null) q.add(curr.right);
}
}
return depth;
}
}