Minimum Depth of Binary Tree

Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. Note: A leaf is a node with no children. Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its minimum depth = 2. Solution: Recursion /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public int minDepth(TreeNode root) { if (root == null) return 0; int left = minDepth(root.

by lek tin in "algorithm" access_time 2-min read

Maximum Depth of Binary Tree

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. NOTE: A leaf is a node with no children. Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its minimum depth = 3. Solution: recursion /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public int maxDepth(TreeNode root) { if (root == null) return 0; int left = maxDepth(root.

by lek tin in "algorithm" access_time 1-min read