#include "s0111_minimum_depth_of_binary_tree.hpp"

int S0111::minDepth(TreeNode* root) {
  if (root == nullptr) return 0;
  if (root->left == nullptr && root->right != nullptr) {
    return minDepth(root->right) + 1;
  } else if (root->left != nullptr && root->right == nullptr) {
    return minDepth(root->left) + 1;
  } else {
    return min(minDepth(root->left), minDepth(root->right)) + 1;
  }
}