Given the root of a binary tree, return the minimum depth of the tree.

The minimum depth is the number of nodes along the shortest path from root down to the nearest leaf node. A leaf node is a node that has no children.

Note: A leaf node is defined as a node with neither a left child nor a right child.

Constraints:

• The number of nodes in the tree is in the range $[0, 10^5]$.

• $-1000 \leq$ Node.val $\leq 1000$

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.