111. Minimum Depth of Binary Tree LeetCode Solution

In this guide, you will get 111. Minimum Depth of Binary Tree LeetCode Solution with the best time and space complexity. The solution to Minimum Depth of Binary Tree problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Problem Statement
Complexity Analysis
Minimum Depth of Binary Tree solution in C++
Minimum Depth of Binary Tree solution in Java
Minimum Depth of Binary Tree solution in Python
Additional Resources

111. Minimum Depth of Binary Tree LeetCode Solution image

Problem Statement of 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 1:

Input: root = [3,9,20,null,null,15,7]
Output: 2

Example 2:

Input: root = [2,null,3,null,4,null,5,null,6]
Output: 5

Constraints:

The number of nodes in the tree is in the range [0, 105].
-1000 <= Node.val <= 1000

Complexity Analysis

Time Complexity: O(n)
Space Complexity: O(h)

111. Minimum Depth of Binary Tree LeetCode Solution in C++

class Solution {
 public:
  int minDepth(TreeNode* root) {
    if (root == nullptr)
      return 0;
    if (root->left == nullptr)
      return minDepth(root->right) + 1;
    if (root->right == nullptr)
      return minDepth(root->left) + 1;
    return min(minDepth(root->left), minDepth(root->right)) + 1;
  }
};
/* code provided by PROGIEZ */

111. Minimum Depth of Binary Tree LeetCode Solution in Java

class Solution {
  public int minDepth(TreeNode root) {
    if (root == null)
      return 0;
    if (root.left == null)
      return minDepth(root.right) + 1;
    if (root.right == null)
      return minDepth(root.left) + 1;
    return Math.min(minDepth(root.left), minDepth(root.right)) + 1;
  }
}
// code provided by PROGIEZ

111. Minimum Depth of Binary Tree LeetCode Solution in Python

class Solution:
  def minDepth(self, root: TreeNode | None) -> int:
    if not root:
      return 0
    if not root.left:
      return self.minDepth(root.right) + 1
    if not root.right:
      return self.minDepth(root.left) + 1
    return min(self.minDepth(root.left), self.minDepth(root.right)) + 1
 # code by PROGIEZ