problem
111. Minimum Depth of Binary Tree
code
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int minDepth(TreeNode* root) { if(!root) return 0; if(!root->left) return 1+minDepth(root->right); if(!root->right) return 1+minDepth(root->left); return 1+min(minDepth(root->left), minDepth(root->right)); } };